National Fire Protection Association · 2012. 12. 1. · Mike Holt, Mike Hold Enterprises 12-15a...

National Fire Protection Association 1 Batterymarch Park, Quincy, MA 02169-7471 Phone: 617-770-3000 • Fax: 617-770-0700 • www.nfpa.org

AGENDA

NEC Code-Making Panel 12

Report on Comment Meeting

Dates: November 28 – December 1, 2012

Redondo Beach, CA

Panel 12 will have four Task group meetings on Wednesday, November 28, 2012 with the full panel meeting starting on Thursday, November 29, 2012.

Article 646 Task Group – 8am to 10 am Article 645 Task Group – 10am to 12pm Article 625 Task Group – 1pm to 3pm Editorial Task Group – 3pm to 5pm

Item No. Subject 12-11-1 Call to Order – Chair – Timothy M. Croushore 12-11-2 Introduction of Members and Guests – Chair - Croushore 12-11-3 Review of Meeting Procedures and Revision Schedule – NFPA Staff 12-11-4 Comments/Questions from Committee Members and/or Guests 12-11-5 Task Group Reports 1. Article 646 Modular Data Centers Task Group – John Kovacik 2. Article 645 Information Technology Equipment Re-organization Task Group – Stan Kauffman 3. Article 625 Electric Vehicle Task Group – Gery Kissel 4. Editorial Task Group – Tim Croushore 12-11-6 Processing of Comments for NEC 2014 (Order Determined by Editorial Task Group) 12-11-7 Fire Protection Research Foundation Requests – NFPA Staff

12-11-8 Old Business 12-11-9 New Business 12-11-10 Adjournment

Report on Comments – June 2013 NFPA 70_______________________________________________________________________________________________12-1 Log #165 NEC-P12

_______________________________________________________________________________________________Technical Correlating Committee on National Electrical Code®,

12-10The Correlating Committee directs that the panel clarify the panel action with regard to the specific

text that is to be added and deleted in 610.31.This is a direction from the National Electrical Code Technical Correlating Committee in accordance

with 3.4.2 and 3.4.3 of the Regulations Governing Committee Projects.

_______________________________________________________________________________________________12-2 Log #1031 NEC-P12

_______________________________________________________________________________________________Mike Holt, Mike Hold Enterprises

12-15aReject the addition of the second informational note.

This informational note is unnecessary. Do we really need a note that tells me that a different note is anote? When does it end? Should we add this note in front of all of the informational notes in the Code? “

_______________________________________________________________________________________________12-3 Log #611 NEC-P12

_______________________________________________________________________________________________James F. Williams, Fairmont, WV

12-15a

Includes audible and visual equipment such as chimes, gongs, lights, and displays, and voice outputthat convey information to the user.

A lot of modern (and not so modern) elevator equipment uses recorded or generated speech to alertpassengers.

_______________________________________________________________________________________________12-4 Log #604 NEC-P12


12-15a

Informational Note No. 1: The motor controller, motion controller, and operation controller are located in a singleenclosure or a combination of enclosures.Informational Note No. 2: Informational Note Figure 620.2 is for information only.

If the reader doesn't understand that is informational only, then howdoes this Informational Note help?

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_______________________________________________________________________________________________James T. Dollard, Jr., IBEW Local 98

12-17Continue to Accept.

This comment is submitted on behalf of the high voltage task to provide additional substantiation asdirected by the Correlating Committee.

The High Voltage Task Group (HVTG) was charged with developing recommendations throughout the NEC to providethe code user with prescriptive requirements for high voltage installations. The task group charge was to identify holes inthe code with respect to installations operating at over 600-volts and address them with recommended requirements toallow for uniform installation and enforcement. Small Wind Electric Systems and Solar Photovoltaic (PV) Systems arecurrently being installed at DC voltages over 600V up to and including 1000V, 1200V, 1500V, and 2000V DC. These DCsystems are expanding and have become a more integral part of many structures. Small Wind Electric Systems andSolar Photovoltaic (PV) Systems are employed regularly in, and on all types of structures from dwellings units, to largeretail and high rise construction.

The first direction that the HVTG took was to simply suggest revisions in Chapter 6 for Special Equipment. It isextremely important to fully understand the outline form of the NEC. Section 90.3 mandates that Chapters 1 through 4apply generally and Chapters 5, 6 and 7 are special and serve only to modify or supplement the rules in Chapters 1through 4. The HVTG quickly realized that it was not feasible to address all of the installation requirements in Chapter 6.The work needs to be done throughout the NEC. The special systems in Chapter 6 are built primarily upon Chapters 1through 4 with the Chapter 6 requirements providing only modifications or supplemental requirements. A quick review ofthe UL White-book for electrical products will uncover that UL has many products that are utilized in these systems ratedat and above 600-volts including but not limited to, 600Vdc terminal blocks, 1000Vdc PV switches, 1500Vdc PV fuses,and 2000V PV wiring. Product listings provide permitted uses and restrictions on a given product. The NEC mustrecognize those products through installation requirements. Electrical safety in the home, workplace and in all venuesdepends upon installation requirements to ensure that all persons and property are not exposed to the hazards ofelectricity. The success of this code hinges on three things (1) product standards, (2) installation requirements and (3)enforcement. The NEC needs to recognize emerging technologies that are operating at over 600-volts. Everyone needsto play a role in this transition. The present NEC requirements would literally require that a PV system operating at750-volts DC utilize a disconnecting means rated at 5 kV. The manufacturers, research and testing laboratories and theNEC must work together to develop installation requirements and product standards to support these emergingtechnologies.

Moving the NEC threshold from 600 volts to 1000 volts will not, by itself, allow the immediate installation of systems at1000-volts. Equipment must first be tested and found acceptable for use at the higher voltage(s). The testing and listingof equipment will not, by itself, allow for the installation of 1000 volt-systems. The NEC must include prescriptiverequirements to permit the installation of these 1000-volt systems. It will take both tested/listed equipment and aninstallation code to meet the needs of these emerging technologies that society demands. The installation code shouldbe the NEC.

Moving the NEC to 1000 volts is just the beginning. The desire to keep increasing efficiencies will continue to drive upthe system voltages. We are beginning to see 1200, 1500, and 2000-volt systems. 2500 volts cannot be far down theroad. Most equipment standards are still at 600 volts and will need to be upgraded also.

If the NEC does not adequately address systems over 600 volts, some other standard will. If we want to control thefuture safety of installations over 600 volts we need to address these issues today.


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12-18Continue to Accept in Principle.








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12-18aThe Correlating Committee directs that 620.5 be rewritten in mandatory language to comply with

the NEC Style Manual.In addition, the text as proposed conflicts with the Article 100 definition of "Exposed Live Parts" since exposed live

parts are not suitably guarded or insulated.This is a direction from the National Electrical Code Technical Correlating Committee in accordance


_______________________________________________________________________________________________12-8 Log #348 NEC-P12

_______________________________________________________________________________________________Andy Juhasz, Kone, Inc.

12-18a620.5 Working Clearances. Working space shall be provided about controllers, disconnecting

means, and other electrical equipemnt. The mimimum working space shall be not less thant hat specified in 110.26(A).The clearance requirements of 110.26(A) shall be waived Wwhere conditions of maintenance and supervision ensurethat onlyqualified persons examine, adjust, service and maintain the equipment, the clearance requirements of 110.26(A) shallbe waived as permitted in 620.5(A) through (D) and:(A) Flexible Connections to Equipment. Electrical equipment in (A)(1) through (A)(4) shall be permitted to be is providedwith flexible leads to all external connections so that it can be repositioned to meet the clear working spacerequirements of 110.26(A):(1) Controllers and disconnecting means for dumbwaiters, escalators, moving walks, platform lifts and stairway chairliftsinstalled in the same space witht he driving machine(23) Controllers and disconnecting means for elevators installed in the hoistway or on the care(3) Controllers for door operators(4) Other electrical equipment installed in the hoistway or on the car; or(B) Guards. Live parts of the electrical equipment are suitably guarded, isolated, or insulated, and the equipment can beexamined, adjusted, serviced, or maintained while energized without removal of this protection. or

Informational Note: See definition of Exposed in Article 100(C) Examination, Adjusting, and Servicing. Electrical equipment is not required to be examined, adjusted, serviced, ormaintained while energized. or(D) Low Voltage. Uninsulated parts are at a voltage not greater than 30 volts rms, 42 volts peak, or 60 volts dc.

620.5 has been rewritten in mandatory language to comply with the NEC Style Manual and has notadded the word "exposed" so as not to create any conflicts with the definitions in Article 100. This is being submitted onbehalf of Andy Juhasz and Tim Croushore to address the comments of the TCC.


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12-19aConductors shall have an ampacity in accordance

with 620.13(A) through (D). With generator field control, the conductor ampacity shall be based on the nameplatecurrent rating of the driving motor of the motor-generator set that supplies power to the elevator motor.Informational Note No. 1: The heating of conductors depends on root-mean-square current values, which, withgenerator field control, are reflected by the nameplate current rating of the motor-generator driving motor rather than bythe rating of the elevator motor, which represents actual but short-time and intermittent full-load current values.

Conductors supplying a single motor shall have an ampacity not lessthan the percentage of motor nameplate current determined from 430.22(A) and (E).Informational Note: Some elevator motor currents, or those of similar functions, exceed the nameplate value, butbecause they are inherently intermittent duty and the heating of the motor and conductors is dependent on theroot-mean-square (rms) current value, conductors are sized for duty cycle service as shown in Table 430.22(E).

Conductors supplying a single motor controller shall have anampacity not less than the motor controller nameplate current rating, plus all other connected loads. Motor controllernameplate current rating shall be permitted to be derived based on the rms value of the motor current using anintermittent duty cycle and other control system loads, if present.

Conductors shall have an ampacity in accordance with 620.13(A)through (D). With generator field control, the conductor ampacity shall be based on the nameplate current rating of thedriving motor of the motor-generator set that supplies power to the elevator motor.Informational Note No. 1: The heating of conductors depends on root-mean-square rms current values, which, withgenerator field control, are reflected by the nameplate current rating of the motor-generator driving motor rather than bythe rating of the elevator motor, which represents actual but short-time and intermittent full-load current values.

Conductors supplying a single motor shall have an ampacity not less than thepercentage of motor nameplate current determined from 430.22(A) and (E).Informational Note: Some elevator motor currents, or those of similar functions, exceed the nameplate value, butbecause they are inherently intermittent duty and the heating of the motor and conductors is dependent on theroot-mean-square (rms) current value, conductors are sized for duty cycle service as shown in Table 430.22(E).

Conductors supplying a single motor controller shall have anampacity not less than the motor controller nameplate current rating, plus all other connected loads. Motor controllernameplate current rating shall be permitted to be derived based on the rms value of the motor current using anintermittent duty cycle and other control system loads, if present

'rms' is never referenced in the rest of the text in connection with current, only with voltage. 'rms' is notreally related to duty cycle as suggested in (A).

__OR__The dominate form of reference to root-mean-square is rms in the rest of the text.


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12-19bAdd an asterisk in the second column title as follows "Demand Factor*" and revise the Information

Note as follows:Informational Note: *Demand factors are based on 50 percetn duty cycle (i.e., half time on and half time off)

The note to Table 620.14 has been clarified as shown in the proposal. This is being submitted on behalfof Andy Juhasz and Tim Croushore to address the comments of the TCC.

_______________________________________________________________________________________________12-11 Log #167 NEC-P12


12-19bThe Correlating Committee directs the panel clarify the note based upon 2.3.1 and 3.1.1 of the

NEC Style Manual with respect to mandatory text.This is a direction from the National Electrical Code Technical Correlating Committee in accordance


_______________________________________________________________________________________________12-12 Log #168 NEC-P12


12-28The Correlating Committee directs that the panel write the Exception in a complete sentence to

comply with the last sentence in 3.1.4.1 of the NEC Style Manual.

This is a direction from the National Electrical Code Technical Correlating Committee in accordancewith 3.4.2 and 3.4.3 of the Regulations Governing Committee Projects.


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12-28Revise text to read as follows:

620.21 Wiring Methods. Conductors and optical fibers located in hoistways, in escalator and moving walk wellways, inplatform lifts, stairway chairlift runways, machinery spaces, control spaces, in or on cars, in machine rooms and controlrooms, not including the traveling cables connecting the car or counterweight and hoistway wiring, shall be installed inrigid metal conduit, intermediate metal conduit, electrical metallic tubing, rigid nonmetallic conduit, or wireways, or shallbe Type MC, MI, or AC cable unless otherwise permitted in 620.21(A) through (C).Exception: Cords and cables of Llisted cord and plug connected equipment shall not be required to be installed in araceway.(A) Elevators.(1) Hoistways.(a) Cables used in Class 2 power-limited circuits shallbe permitted to be installed between risers and signalequipment and operating devices, provided the cables aresupported and protected …

The exception to 620.21 has been written as a complete sentence. This is being submitted on behalf ofAndy Juhasz and Tim Croushore to address the comments of the TCC.

_______________________________________________________________________________________________12-14 Log #613 NEC-P12


12-28Conductors and optical fibers located in hoistways, in escalator and

moving walk wellways, in platform lifts, stairway chairlift runways, machinery spaces, control spaces, in or on cars, inmachine rooms and control rooms, not including the traveling cables connecting the car or counterweight and hoistwaywiring, shall be installed in rigid metal conduit, intermediate metal conduit, electrical metallic tubing, rigid nonmetallicconduit, or wireways, or shall be Type MC, MI, or AC cable unless otherwise permitted in 620.21(A) through (C).

The new exception is the size of a barn door. It would allow microwaves, curling irons, and blenders inelevator shafts with standard cordage. It is completely out of line with the almost 3 pages of requirements for wiring in620.21.


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12-37The Correlating Committee directs that this proposal be reconsidered and correlated with the action

taken on Proposal 12-39.This is a direction from the National Electrical Code Technical Correlating Committee in accordance


_______________________________________________________________________________________________12-17 Log #350 NEC-P12



(1) On Elevators Without Generator Field Control. On elevators without generator field control, the disconnecting meansshall be located within sight of the motor field controller. Where the motor controller is located in the elevator hoistway,the disconnecting means required by 620.51(A) shall be located in a machinery space, machine room, control space orcontrol room outside the hoistway; and an additional, fused or non-fused externally operable motor circuit switch that islockable open in accordance with 110.25 capable of being locked in the open position to disconnect all ungroundedmain power-supply conductors shall be located within sight of the motor controller. The additional switch shall be a listeddevice and shall comply with 620.91(C).The provision for locking or adding a lock to the disconnecting means, required by this section, shall be installed on or atthe switch or circuit breaker used as the disconnecting means and shall remain in place with or without the lockinstalled. Portable means for adding a lock to the switch or circuit breaker shall not be permitted.Driving machines or motion and operation controllers not within sight of the disconnecting means shall be provided witha manually operated switch installed in the control circuit to prevent starting. The manually operated switch(es) shall beinstalled adjacent to this equipment.Where the driving machine of an electric elevator or the hydraulic machine of a hydraulic elevator is located in a remotemachine room or remote machinery space, a single means for disconnecting all ungrounded main power supplyconductors shall be provided and be lockable open in accordance with 110.25. capable of being locked in the openposition.

Proposal 12-37 has been correlated with proposal 12-39 to show the complete final wording. This isbeing submitted on behalf of Andy Juhasz and Tim Croushore to address the comments of the TCC.

_______________________________________________________________________________________________12-18 Log #1235 NEC-P12

_______________________________________________________________________________________________Richard E. Loyd, Sun Lakes, AZ

2-46Reconsider and Accept this proposal or accept in part . accept “The disconnecting means shall be

an enclosed externally operable fused motor circuit switch or circuit breaker capable of being locked in the open positionand shall be located in the machine room or control room for that elevator car”.

While attending the Southern section IAEI meeting this change was explained and it seems theproposed text from the submitter is much clearer than the wording revised by the committee.


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_______________________________________________________________________________________________Joseph M. Bablo, UL LLC


Informational Note No. 2: UL 2594-20112012, , is a safety standard forElectric Vehicle Supply Equipment. UL 2202-2009, , is asafety standard for Electric Vehicle Charging Equipment.

The referenced date in the proposal would not be correct. The actual date for the standard would be2012.

_______________________________________________________________________________________________12-20 Log #776 NEC-P12

_______________________________________________________________________________________________Gregory C. Nieminski, Gregory C. Nieminski, LLC


An apparatus designed to control and organize unused lengths of cable or cord atelectric vehicle charging sites.

The term "cable management system” has been used in the new Article 62.5.17(C) but is not defined.The term is presently used and defined in Article 626. It is proposed that the same definition be added to 625.2 or,alternatively, that the term be defined commonly in Article 100.

This comment is submitted on behalf of the EPRI Electric Transportation Infrastructure Working Council's NEC TaskForce.

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_______________________________________________________________________________________________Marcelo M. Hirschler, GBH International


An automotive-type vehicle for on-road use, such as passenger automobiles, buses, trucks, vans,neighborhood electric vehicles, electric motorcycles, and the like, primarily powered by an electric motor that drawscurrent from a rechargeable storage battery, fuel cell, photovoltaic array, or other source of electric current. Plug-inhybrid electric vehicles (PHEV) are considered electric vehicles. For the purpose of this article, off-road, self-propelledelectric vehicles, such as industrial trucks, hoists, lifts, transports, golf carts, airline ground support equipment, tractors,boats, and the like, are not included.

Plug-in hybrid electric vehicles (PHEV) shall be considered electric vehicles.For the purpose of this article, off-road, self-propelled electric vehicles, such as industrial trucks, hoists, lifts,

transports, golf carts, airline ground support equipment, tractors, boats, and the like, are not included.Both the electric vehicle connector and the electric vehicle inlet shall be considered a part of the electric vehicle

coupler.For the purposes of this Code, the electric vehicle inlet shall be considered to be part of the of the electric

vehicle and not part of the electric vehicle supply equipment.I accept the concept that NEC definitions are not required to be in single sentences. However this

definition contains a list of examples and such examples are not usually contained in definitions. Moreover, theinformation included should really be considered a requirement. If the CMP agrees that this is a requirement it should beplaced somewhere else in Article 625, and a new section 625.3, on general requirements, is the perfect location, sinceNEC definitions shall not contain requirements. Moreover, the NEC manual of style does not permit the definition tocontain the defined term and the second sentence of the definition contains the term “electric vehicle”. The sections in625.3.3 and 625.3.4 are associated with the comments to proposals 12-55 and 12.56.The NEC Manual of Style states as follows:

Definitions. Definitions shall be in alphabetical order and shall not contain the term that is being defined.Definitions shall not contain requirements or recommendations.

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A device that, by insertion into an electric vehicle inlet, establishes an electricalconnection to the electric vehicle for the purpose of power transfer and information exchange. This device is part of theelectric vehicle coupler.





definition contains a requirement. If the CMP agrees that this is a requirement it should be placed somewhere else inArticle 625, and a new section 625.3, on general requirements, is the perfect location, since NEC definitions shall notcontain requirements. Moreover, the NEC manual of style does not permit the definition to contain the defined term. Thesections in 625.3.1 through 625.3.4 are associated with the comments to proposals 12-54 and 12.56 also.The NEC Manual of Style states as follows:


_______________________________________________________________________________________________12-23 Log #774 NEC-P12



Electric Vehicle Connector Electric Vehicle ConnectorIt appears that the term was crossed out inadvertently in the NEC Committee Report on Proposals,

A2013 (page 70-658 ,printed version), and should remain.This comment is submitted on behalf of the EPRI Electric Transportation Infrastructure Working Council's NEC Task

Force.

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The device on the electric vehicle into which the electric vehicle connector is inserted for powertransfer and information exchange. This device is part of the electric vehicle coupler. For the purposes of this theelectric vehicle inlet is considered to be part of the electric vehicle and not part of the electric vehicle supply equipment.





definition contains a set of requirements. If the CMP agrees that this is a requirement it should be placed somewhereelse in Article 625, and a new section 625.3, on general requirements, is the perfect location, since NEC definitions shallnot contain requirements. Moreover, the NEC manual of style does not permit the definition to contain the defined termand the second sentence of the definition contains the term “electric vehicle inlet”. The sections in 625.3.1 through625.3.4 are associated with the comments to proposals 12-54 and 12.55 also.The NEC Manual of Style states as follows:


_______________________________________________________________________________________________12-25 Log #1375 NEC-P12

_______________________________________________________________________________________________Vince Baclawski, National Electrical Manufacturers Association (NEMA)

12-52Add new definition:

Fastened In Place: equipment attached to a structure but removable without the use of tools, where the fasteningmeans are specifically designed to facilitate the following:a. Ready removal for interchangeb. Facilitate maintenance and repairc. Repositioning to another location

The term or phrase “fastened in place” is not defined and subject to misinterpretation. The definition isneeded for consistency throughout article 625.

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An assembly consisting of an attachment plug cap and length of flexible cord that connects theequipment (E SE) to a receptacle.

The term "attachment plug cap" appears only once in Article 625 in this definition. The primary term"attachment plug" is used everywhere else in Article 625 and should be used here for consistency. It is also thepredominant term used in the NEC and defined in Article 100:

Attachment Plug (Plug Cap) (Plug). A device that, by insertion in a receptacle, establishes a connection between theconductors of the attached flexible cord and the conductors connected permanently to the receptacle.

Attachment plug cap is a term referring to an older design of an attachment plug that permitted the flexible cord to beknotted for strain relief purposes and covered by a "cap" that was part of the attachment plug assembly. The term is notused in LZ 191. Standard for Attachment Plugs and Receptacles, nor is the method of using a knot for strain reliefpurposes included in the Standard.


_______________________________________________________________________________________________12-27 Log #797 NEC-P12



The electric vehicle coupler shall comply with 625.10(A) through (F).The electric vehicle coupler shall be polarized unless part of a listed electric vehicle charging system

or an electric vehicle supply equipment system.Exception: A coupler that is listed as part of the electric vehicle supply equipment.

The intent of this clause would be that the coupler shall be polarized, but a non-polarized version isacceptable if part of a system that is listed. The word “unless” as indicated in the original proposal would infer that thecoupler shall be polarized if part of a system that is not listed and non-polarized if part of a listed system. That is not theintent of the requirement. The proposed wording eliminates this possible interpretation of the clause by adding anexception that is identical to the format used in other parts of the article (see 625.17(A)(1) for example).

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_______________________________________________________________________________________________Ken Jensen, Portland, OR

12-52Revise 625.14 as follows:

"625.14 Rating. Electrical vehicle supply equipment shall have sufficient rating to supply the load served. Electricvehicle charging loads shall be considered to be continuous loads for the purposes of this article. Where an automaticload management system is used, the maximum electric vehicle supply equipment load on a service or feeder or branchcircuit shall be the maximum load permitted setting in use or communicated by the automatic load management system.

The original TIA sentence in question is copied below:"Where an automatic load management system is used, the maximum electric vehicle supply equipment load on aservice or feeder shall be the maximum load permitted by the automatic load management system."The first use of the word "maximum" is clear but, the second use of the word "maximum" is confusing when applied toElectric Vehicle Supply Equipment. Replacing the words "maximum load permitted" with "setting in use orcommunicated" clarify the intent of the NEC.I found there are two (2) ways of understanding or interpreting this "maximum load permitted" wording within TIA 1038for NEC 625.14.Today many EVSEs on-board chargers are built to use the standard called "Society of Automotive Engineers J1772".This standard addresses the problem that different premises EVSEs will have different rated ampacities and differentelectric vehicles will have different loads. SAE J1772 allows many combinations to interconnect with each other byhaving the premises EVSE communicate or provide to the electric vehicle on-board charger how much ampacity isavailable from that premises EVSE. Then the electric vehicle on-board charger must adjust or regulate the load so thatis less than or equal to the available premises EVSE ampacity.The following text is copied from two (2) revisions of that standard.SAE J1772 2001"5.3.5 EVSE Current Capacity - The EVSE provides the maximum available continuous current capacity, and byinference the rating of the protective circuit breaker, to the EV by modulating the pulse width..."SAE J1772 2010"5.3.5 EVSE Current capacity - The EVSE communicates the maximum available continuous current capacity to theEV/HEV by modulating the pilot duty cycle..."Some EVSEs are built to offer a single fixed large communicated available current. However many EVSEs offermultiple or adjustable settings of communicated available current. One common EVSE I know of offers 15amp or 8ampsettings. A second common EVSE I know of offers 12 amp, 16 amp, 24 amp, or 30 amp settings.Every single one of these different values is a maximum current value. So an EVSE with multiple settings has a groupof maximum current values. The group also has a maximum of all the maximum current values.Which meaning does TIA 1038 NEC 625.14 maximum mean? Is the maximum electric vehicle supply equipment loadthe real setting of the EVSE?Is the maximum electric vehicle supply equipment load the largest possible, worst case setting of the EVSE?Replacing "maximum load permitted" with "setting or communicated" means the NEC 625.14 will allow a versatileinstallation of low demand low ampacity or medium demand medium ampacity, or high demand high ampacity.Adding the wording "or branch circuit" to NEC 625.14 text simply reflect a common practice. EVSEs are often installedon a branch circuit.

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The electric vehicle supply equipment shall comply with 625.15(A) through (C).Where marking is required by 625.29(C) 625.52(A), the electric vehicle supply

equipment shall be clearly marked by the manufacturer as follows:VENTILATION NOT REQUIREDThe marking shall be located so as to be clearly visible after installation.

The reference given is part of the old text and was not updated to the new renumbering structure ofthe rewritten article. The proposed reference would point to the correct clause.

_______________________________________________________________________________________________12-30 Log #359 NEC-P12


12-52Delete the exception.A power supply cord that is listed as a part of the electric vehicle supply equipment.

There is no reason to deviate from the requirements of this section. There are already some instancesof product not performing and there is not enough experience to be granting exceptions at this time. In addition theproduct standard is not clear as to this topic. Any and all equipment issues will reflect poorly on the industry and harmthe efforts to promote this product.

_______________________________________________________________________________________________12-31 Log #363 NEC-P12


12-52Delete the article:

Electric vehicle supply equipment that is rated 250 volts maximumand complies with all of the following:1. It is part of a listed system meeting the requirements of 625.18, 625.19, 625.50 and 625.52.

625.44(B)(1) is redundant and could imply that these requirements do not apply to all EVSE, which theydo.

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12-52Delete the exception.A power supply cord that is listed as a part of the electric vehicle supply equipment.

There is no reason to deviate from the requirements of this section. There are already some instancesof product not performing and there is not enough experience to be granting exceptions at this time. In addition theproduct standard is not clear as to this topic. Any and all equipment issues will reflect poorly on the industry and harmthe efforts to promote this product.

_______________________________________________________________________________________________12-33 Log #361 NEC-P12



625.17(C)(2) Where the electric vehicle supply equipment or charging system is fixed in place, the useablelength of the output cable shall be measured from the cable exit of the electric vehicle supply equipment or chargingsystem to the face of the electric vehicle connector. The term fixed in place shall include devices that are permanentlywired as well as devices that are cord and plug connected and fastened in place where the fastening means arespecifically designed to facilitate any of the followinga. Ready removal for interchangeb. Facilitate maintenance and repairc. Repositioning to another location

The existing language could cause confusion. Adding this wording will clarify that the term “fixed inplace” can include cord and plug connected devices and that they are not necessarily restricted by 625.17(C)(1).

_______________________________________________________________________________________________12-34 Log #170 NEC-P12


12-66The Correlating Committee directs that the panel clarify the panel statement on this proposal with

respect to revised definitions for "Electric Vehicle Coupler" and "Electric Vehicle Interlock."This is a direction from the National Electrical Code Technical Correlating Committee in accordance


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_______________________________________________________________________________________________Ken Jensen, Portland, OR

12-52A revised 625.21 as follows:

"625.21 Overcurrent Protection. Overcurrent protection for feeders and branch circuits supplying electric vehicle supplyequipment shall be sized for continuous duty and shall have a rating of not less than 125 percent of the maximum loadof the electric vehicle supply equipment. Where noncontinous loads are supplied from the same feeder or branchcircuit, the overcurrent device shall have a rating of not less than the sum of the noncontinous loads plus 125 percent ofthe continuous loads.Where an automatic load management system is used to time shift multiple loads into sequential loads, the maximumload of the electric vehicle supply equipment shall be the maximum sequential load, for the purposes of this article.

NEC article 100 defines "Continuous Load" to be 3 hours or more. Real world examples of electricvehicle charge times are more than 3 hours, but less than 24 hours.NEC 625 should clarify these questions.May an automatic load management system apply and use time of day control, to prevent multiple simultaneouscontinuous loads and instead create a single sequential non over lapping (time shipping) continuous load? Should allEVSE loads plan to be simultaneous loads?Here is an example of these two (2) questionsAssume the following:A) Two electric vehicles in one garageB) Two EVSEs with automatic load managementC) Both EVSEs are rated 30 amps availableD) Both EVSEs are on the same circuitE) Both EVSE have time of day controlsF) One EVSE is adjusted or set to only provide current from 10 PM to 2 AM (4 hours only)G) One EVSE is adjusted or set to only provide current from 2 AM to 6 AM (4 hours only)The time of day controls are set to never over lap, so the maximum load permitted by the automatic load managementwill be a single sequential 30 amp continuous load.So plan for a 30 amp continuous load.The real measured load is 30 amps for 8 hours.The time of day controls may be reset to enable two simultaneous 30 amp continuous loads.So plan for a 60 amp continuous load.Which of these is the intent of NEC 625.21?

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625.22 Personnel Protection System. The electric vehicle supply equipment shall have a listed system of protectionagainst electric shock of personnel. The personnel protection system shall be composed of listed personnel protectiondevices and constructional features. Where cord-and-plug-connected electric vehicle supply equipment is used, theinterrupting device of a listed personnel protection system shall be provided and shall be an integral part of theattachment plug or shall be located in the power supply cable not more than 300 mm (12 in.) from the attachment plug.

(A) Where cord-and-plug-connected electric vehicle supply equipment, that is intended to be carried from charginglocation to charging location, is used, the interrupting device of a listed personnel protection system shall be providedand shall be an integral part of the attachment plug or shall be located in the power supply cable cord not more than 300mm (12 in.) from the attachment plug.

(B) Where cord-and-plug-connected electric vehicle supply equipment is intended to be installed in a dedicatedlocation for the purpose of charging a vehicle, has a means for temporary mounting and can be dismounted without theuse of a tool, the interrupting device of a listed personnel protection system shall be provided and shall be an integralpart of the attachment plug or shall be located in the power supply cable cord not more than 1.2 m (4 ft) from theattachment plug.

The panel statement recognizes there are conditions where a longer cord can be used safely.EVSEs other than portable units are generally intended to be installed in a dedicated location in order to charge a

vehicle. Some may be moved or relocated after installation without the use of tools (cf. UL 2594), using a mountingmeans similar to that used for relocatable power taps described in UL 1363, Standard for Relocatable Power Taps.Since these units would typically be mounted 0.6-0.9 m (2-3 feet) from the floor when in use, this would allow the safeuse of a longer than 1 foot unprotected power supply cord yet provide adequate physical protection for the power supplycord against damage.

The term “power supply cable” should be changed to “power supply cord” to align with the new definitions.This comment is submitted on behalf of the EPRI Electric Transportation Infrastructure Working Council's NEC Task

Force.

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The electric vehicle supply equipment shall have a listed system of protectionagainst electric shock of personnel. Where cord-and-plug connected electric vehicle supply equipment is used, theinterrupting device of a listed personnel protection system shall be provided and shall be an integral part of theattachment plug or shall be located in the power supply cord not more than 300 mm (12 in.) from the attachment plug,unless the EVSE complies with 625.44(B), in which case the interrupting device may be located within the overall deviceenclosure.

There is a disconnect between three clauses in the article, and this disconnect causes a problem inthe interpretation of the wording in 625.44(B)(4). In order to clarify this intent, the wording is proposed to be added to625.22. Rationale is as follows:

The intent of 625.44(B)(4) was to allow constructions where the interrupting device of the personnel protection systemrequired by 625.22 was located within the device enclosure, but the power cord was allowed to be longer than the 12inches required by 625.17(A)(3)(a), due to the other requirements within 625.44(B).625.17(A)(3)(a) limits the cord length to 12 inches because the interrupting device of the personnel protection systemrequired by 625.22 is located within the device enclosure.625.17(A)(3)(b) allows the cord length to be 6 feet minimum, 15 feet maximum, provided the interrupting device of thepersonnel protection system required by 625.22 is located at the attachment plug or within 12 inches of the attachmentplug.

The current wording in 625.22 supports this.625.44(B) states that a product can be cord connected provided it meets all the subclauses (1) through (5). Subclause

4 states that the power cord shall be maximum 6 feet. All this does is limit the overall length of the power cord to 6 feet.However, the intent of this proposal was to allow for a 6 foot cord length when the interrupting device of the personnelprotection system required by 625.22 was located within the enclosure. This would be a direct violation to625.17(A)(3)(a) based on the current wording. The rationale for the wording in 625.44(B)(4) was that a device fixed inplace, as required by 625.44(B)(3), would protect the cord by limiting the cord to 6 feet thereby keeping it off the floorand protected from abuse. In so doing, the need to protect the cord by limiting it to 12 inches is no longer required.Therefore, 625.44(B)(4) was proposed to allow a 6 foot cord length on products where the interrupting device of thepersonnel protection system was located within the device enclosure, but the device was wall mounted and fixed inplace.

In order to clarify this intent and allow constructions that were intended to be acceptable, the wording in 625.22 isneeded.

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_______________________________________________________________________________________________Joseph C. Engel, Monroeville, PA


Informational Note: The INDEX under Ground-fault protection (Personnel) states “ Ground-fault circuit interrupters”.ARTICLE 100 defines a Ground-Fault Circuit Interrupter (GFCI) as being a CLASS A device. A CLASS A must trip at

6mA or below.The Panel’s Statement in support of rejecting the addition of the words “CLASS A” has missed the

point. While a device can be UL Listed as being either a 6 mA or 30 mA device, NEC allows only a 6 mA “PersonnelProtection System”. Adding the words “CLASS A” doesn’t change the requirement, only further clarifies it. The need forsuch clarification is obvious when one considers that more than half of the EVSEs installed today are in violation of NEC2001 and thus could be considered unsafe.

_______________________________________________________________________________________________12-39 Log #362 NEC-P12


12-52Change the concluding paragraph as follows:

All other electric vehicle supply equipment shall be permanently connected to the premises wiring system wired andfixed in place to the supporting surface, a wall, a pole, or other structure. The electric vehicle supply equipment shallhave no exposed live parts.

The last paragraph is revised to clarify what is not allowed to be cord and plug connected and avoidsdifferent interpretations in the field.

_______________________________________________________________________________________________12-40 Log #823 NEC-P12

_______________________________________________________________________________________________Jeffrey L. Holmes, IBEW Local Union 1 JATC

12-52Delete all of part (B) and reword as follows:

(B) All other electric vehicle supply equipment shall be permanently connected and fastened in place.There was no substantiation for allowing cord and plug connected EVSE up to 50 ampere rating. Most

of the larger branch circuits are protected by the equipment (range & dryer), so that the possibility of unplugging theequipment under load is minimized. This would not be the case with this proposal. The supply side of the EVSE couldbe unplugged, under load, in a constant current status of up to 50 amperes without any safe guards. Treating EVSE asa portable appliance is a safety concern. The TIA and the proposal do not satisfy the intent of Article 625.13. Theproposed 625.44 needs to be evaluated for all safety concerns in both commercial and residential applications.

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(A) Connections to 125-Volt, Single Phase, 15 and 20 Ampere Receptacle Outlets. Electric vehicle supply equipmentintended for connection to non-locking, 2-pole.3-wire grounding type receptacle outlets rate d at 125 volts, single phase,15 and 20 amperes or from a supply of less than 50V DC.

Informational Note: Complete details of these configuration can be found in ANSI/NEMA. WD 6-2002 (R2008), NationalElectrical Manufacturers Association's Wiring Devices-Dimensional Specifications, Figures 5-15, 5-20 and 5-20 ALT.

There are non-grounding type attachment plugs and receptacles available and sold for use with olderpremise wiring systems not provided with a grounding conductor. These 2-pole, 2-wire non-grounding (NEMA 1-15 and1-20) type receptacles also exist as a part of a large installed base (pre-1960) of premise wiring systems havingnon-grounding type receptacles. They are sold only for replacement purposes.

An informational note has been added to identify the correct NEMA configuration for the receptacles.Locking type receptacles should not be used as they can increase the risk of damage to the receptacle and premise

wiring, possibly exposing live parts, if the vehicle were to move while still connected.This comment is submitted on behalf of the EPRI Electric Transportation Infrastructure Working Council's NEC Task

Force.

_______________________________________________________________________________________________12-42 Log #778 NEC-P12



(2) It is intended for connection to non-locking, 2-pole, 3-wire and 3-pole, 4-wire grounding type receptacle outletsrated no more than 50 amperes.

Informational Note: Complete details for these non-locking type, 2-pole, 3-wire and 3-pole, 4-wire grounding typeconfiguration can be found in ANSI/NEMAWD 6-2002 (R2008) National Electrical Manufacturers Association's WiringDevices-Dimensional Specifications.

There are non-grounding type attachment plugs and receptacles available and sold for use with olderpremise wiring systems not provided with a grounding conductor. They are intended only for replacement purposes, notnew installations (i.e. -NEMA 10-30R, 3-pole, 3-wire clothes dryer receptacle). Other 2-pole, 2-wire and 3-pole, 3-wire,single and three phase receptacles that do not provide a means for grounding are also available.

An informational note has been added to identify the correct NEMA configurations for the receptacles.Locking type receptacles should not be used as they can increase the risk of damage to the receptacle and premise

wiring, possibly exposing live parts, if the vehicle were to move while still connected.This comment is submitted on behalf of the EPRI Electric Transportation Infrastructure Working Council's NEC Task

Force.

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(2) It is intended for connection to a receptacle outlets rated no more than 50 amperes."Receptacle outlets" may imply that there can be more than one outlet on the 50A branch circuit. This

would be prohibited by the new Article 219.17 which requires one outlet per circuit.This comment is submitted on behalf of the EPRI Electric Transportation Infrastructure Working Council's NEC Task

Force.

_______________________________________________________________________________________________12-44 Log #364 NEC-P12


12-52Add text to read as follows:

Electric vehicle supply equipment that is listed as Movable and complieswith all of the following:1. It is listed for connection to receptacle outlets rated no more than 50 amperes2. EVSE is listed as movable to facilitate the following:a. Intended to be moved from one position to another between uses

625.44(C) adds an exception for “Movable” Equipment which is defined in UL2594 and would have tobe cord and plug connected by its design.

_______________________________________________________________________________________________12-45 Log #785 NEC-P12



Electric vehicle supply equipment and other parts of a system, either on-board or off-board the vehicle, that areidentified for and intended to be interconnected to a vehicle and also serve as an optional standby system or an electricpower production source or provide for bi-directional power feed shall be listed and marked as “Suitable for BidirectionalPower Feed” suitable for that purpose.

When used as an optional standby system, the requirements of Article 702 shall apply, and when used as an electricpower production source, the requirements of Article 705 shall apply.

The proposal in 12-52 contained the phrase “as suitable for that purpose”, which is vague andunenforceable. Electric vehicle supply equipment intended for bidirectional power feed should be listed and identified bya specific marking to distinguish it from other EVSE that is not suitable for bidirectional power feed.


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(4) Power supply cord length for electric vehicle supply equipment fastened in place is limited to 6 ft (1.8 m) 1.8 m (6ft).

Metric units should be the primary dimension with the English units in parentheses per the stylemanual.


_______________________________________________________________________________________________12-47 Log #781 NEC-P12


12-52Add missing Tables 625.52(B)(1) and 625.52(B)(2) after 625.52(B)(4) Supply Circuits:

***Insert Tables 625.52(B)(1) and 625.52(B)(2) Here***

It appears that the Tables 625.2952(DB)(1) and 625.2952(DB)(2) were not included in the printedversion of NEC Committee Report on Proposals, A2013, and should be added. This may be a printing error and shouldbe corrected to include these two Tables in the recommended text provided by CMP 12, following 625.52(B)(4).


_______________________________________________________________________________________________12-48 Log #782 NEC-P12


12-52Revise Table Heads as follows:

***Insert Table 625.52(B)(2) Here***Although the two tables have been expanded to include a column for up to 50 volts DC, the proposed

Article 625-4 acknowledges DC voltages up to 600 volts. The remaining Single Phase columns in both Tables625.52(B)(1) and 625.52(B)(2) should be revised to include references for DC voltages above 50 volts DC. This can bedone by changing the headings to add Alternating Current or Direct Current in the Single Phase column heading andAlternating Current in the 3-Phase column heading, as was proposed in Proposal Number 12-76 that was “Accepted inPrincipal”. The additional DC voltage values proposed in Proposal Number 12-76 could be added as well at the Panel’sdiscretion.


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70/L781/Tb 625.52(B)(1)/A13/ROC

Table 625.2952(DB)(1) Minimum Ventilation Required in Cubic Meters per Minute (m3/min) for Each of the Total

Number of Electric Vehicles That Can Be Charged at One Time

Branch-

Circuit

Ampere

Rating

Branch-Circuit Voltage

Single Phase 3 Phase

DC Less Than

50 V(17) 120 V 208 V

240 V or

120/240 V

208 V or

208Y/120 V 240 V

480 V or

480Y/277 V

600 V or

600Y/347 V

15 0.5 1.1 1.8 2.1 — — — —

20 0.6 1.4 2.4 2.8 4.2 4.8 9.7 12

30 0.9 2.1 3.6 4.2 6.3 7.2 15 18

40 1.2 2.8 4.8 5.6 8.4 9.7 19 24

50 1.5 3.5 6.1 7.0 10 12 24 30

60 1.8 4.2 7.3 8.4 13 15 29 36

100 2.9 7.0 12 14 21 24 48 60

150 — — — 31 36 73 91

200 — — — 42 48 97 120

250 — — — 52 60 120 150

300 — — — 63 73 145 180

350 — — — 73 85 170 210

400 — — — 84 97 195 240

Page 32 of 75

70/Log #781/Tb 625.52(B)(2)/A2013/ROC

Table 625.2952(DB)(2) Minimum Ventilation Required in Cubic Feet per Minute (cfm) for Each of the Total Number of Electric

Vehicles That Can Be Charged at One Time

Branch-

Circuit Ampere

Rating


Single Phase 3 Phase

DC Less

Than 50 V (17) 120 V 208 V

240 V or

120/240 V

208 V or

208Y/120 V 240 V

480 V or

480Y/277 V

600 V or

600Y/347 V

15 15.4 37 64 74

20 20.4 49 85 99 148 171 342 427

30 30.8 74 128 148 222 256 512 641

40 41.3 99 171 197 296 342 683 854

50 51.3 123 214 246 370 427 854 1066

60 61.7 148 256 296 444 512 1025 1281

100 102.5 246 427 493 740 854 1708 2135

150 — — — 1110 1281 2562 3203

200 — — — 1480 1708 3416 4270

250 — — — 1850 2135 4270 5338

300 — — — 2221 2562 5125 6406

350 — — — 2591 2989 5979 7473

400 — — — 2961 3416 6832 8541

Page 33 of 75

NEC/L782/Tb 625.52(B)(2)/A13/ROC

Table 625.52(B)(1) and 625.52(B)(2) Change Table headings to include references for DC

voltages:

Branch-

Circuit

Ampere

Rating


DC Less Than 50 V Single Phase Alternating Current

Or Direct Current

3 Phase Alternating Current

(17)

(T he rem ainder of the table and values would be unchanged)

Page 34 of 75




A device that, by inserting it into a truck flanged surface inlet, establishes an electrical connection tothe truck for the purpose of providing power for the on-board electric loads and may provide a means for informationexchange. This device is part of the truck coupler.

Cord connectors shall be considered a part of the truck coupler.Truck flanged surface inlets shall be considered a part of the truck coupler.

For the purposes of this article, the truck flanged surface inlet is considered to be part of the truck and not partof the electrified truck parking space supply equipment.

I accept the concept that NEC definitions are not required to be in single sentences. However thisdefinition contains a requirement. If the CMP agrees that this is a requirement it should be placed somewhere else inArticle 626, and a new section under 625.4, on general requirements, is the perfect location, since NEC definitions shallnot contain requirements. Moreover, the NEC manual of style does not permit the definition to contain the defined term.The sections 626.4.2 and 626.4.3 are associated with the comment to proposal 12-82.The NEC Manual of Style states as follows:


_______________________________________________________________________________________________12-50 Log #484 NEC-P12



The device(s) on the truck into which the cord connector(s) is inserted to provide electricenergy and other services. This device is part of the truck coupler. For the purposes of this article, the truck flangedsurface inlet is considered to be part of the truck and not part of the electrified truck parking space supply equipment.

Cord connectors shall be considered a part of the truck coupler.Truck flanged surface inlets shall be considered a part of the truck coupler.For the purposes of this article, the truck flanged surface inlet is considered to be part of the truck and not part

of the electrified truck parking space supply equipment.I accept the concept that NEC definitions are not required to be in single sentences. However this

definition contains a requirement. If the CMP agrees that this is a requirement it should be placed somewhere else inArticle 626, and a new section under 625.4, on general requirements, is the perfect location, since NEC definitions shallnot contain requirements. Moreover, the NEC manual of style does not permit the definition to contain the defined term.The section 626.4.1 is associated with the comment to proposal 12-81.The NEC Manual of Style states as follows:


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12-79Delete the following text:

626.5 The equipment located in the electrified truck parking spaces shall be permitted to be used for charging electricvehicles. Additional electric vehicle supply equipment (EVSE) shall be permitted to be located in these spaces.

NEMA opposes the panel action on proposal 12-79 (626.1) that creates a new 626.5 Electric VehicleCharging article.This proposal could create a safety issue as the wording of the proposed article 626.5 allow EV charging equipment inelectrified truck parking spaces without demanding that it satisfies all the relevant requirements of article 625.

_______________________________________________________________________________________________12-52 Log #784 NEC-P12


12-86We support the panel action to reject Proposal 12-86.

We agree with the panel’s comment reaffirming its intent to have a maximum of 3 receptacles on twodifferent branch circuits. The original intent of the original article requiring two single receptacles was to minimize thenumber of connections from the truck parking space supply equipment to the truck or trucks in adjacent parking spaces.Each receptacle was intended to be connected to its own individual branch circuit.

Serious injury can occur to the operator or repairman if one of the multiple supply sources is not disconnected or itsbranch circuit is not opened during repair or maintenance. Minimizing the number of circuits connected to the truck willreduce the risk of such hazard.


_______________________________________________________________________________________________12-53 Log #614 NEC-P12


12-93A disconnecting means shall be provided in the supply circuit for

each arc welder that is not equipped with a an integral disconnect mounted as an integral part of the welder and. Eachexternal disconnect shall be marked to identify what arc welder it disconnects.

Text is extremely awkward.

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_______________________________________________________________________________________________Thomas M. Burke, UL LLC

12-19Revise the Information Note 2 associated with requirements for listing of amplifiers to add a

reference to the new standard, UL 62368-1.Informational Note No. 2: Examples of requirements for listing amplifiers used in residential, commercial, and

professional use are found in ANSI/UL 813-1996, ; ANSI/UL 1419-2011,; ANSI/UL 1492-2010, ; and ANSI/UL 6500-2006,

and UL 62368-1-2012,

This is one in a series of proposals to update NFPA 70 to add a reference to UL 62368-1.ANSI/UL 62368-1, Audio/video, information and communication technology equipment – Part 1: Safety requirements,

was published on February 17, 2012. This new standard will eventually replace (later this decade) both, UL 60065,Audio, Video, and Similar Electronic Apparatus-Safety Requirements, and UL 60950-1, Information TechnologyEquipment Safety - Part 1: General Requirements. In the meantime, multiple references to UL 6500 and UL 60950-1 inthe body of the Code should be supplemented by a reference to UL 62368-1 since similar equipment complying with,and Listed to both standards will be installed per the Code. In fact, equipment already is being Listed to UL 62368-1.

_______________________________________________________________________________________________12-55 Log #171 NEC-P12


12-109The Correlating Committee directs that this proposal be reconsidered and reviewed in its entirety

for compliance with the NEC Style Manual.Numbering between Parts should start, at minimum, with the next decade in accordance with the NEC Style Manual.The Correlating Committee directs the panel to reconsider the titles for both Parts II and Parts III to improve clarity.The term "power grounding" should also be reconsidered since it is not defined in the NEC.


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_______________________________________________________________________________________________Stanley Kaufman, CableSafe, Inc.

12-109Continue CMP 12 action to Accept In Principle and modify the text as shown:

Informational Note: Text that is followed by a reference in brackets has been extracted from NFPA 75-2009,. Only editorial changes were made to the extracted text to make

it consistent with this .

This article covers equipment, power-supply wiring, equipment interconnecting wiring, and grounding ofinformation technology equipment and systems in an information technology equipment room.

Informational Note: For further information, see NFPA 75-2009,, which covers the requirements for the protection of information technology equipment and information

technology equipment areas.

Installed supply circuits and interconnecting cables that arenot terminated at equipment and not identified for future use with a tag.

An information technology equipment system that requires continuous operation forreasons of public safety, emergency management, national security, or business continuity.

Equipment and systems rated 600 volts or less, normally found in offices orother business establishments and similar environments classified as ordinary locations, that are used for creation andmanipulation of data, voice, video, and similar signals that are not communications equipment as defined in Part I ofArticle 100 and do not process communications circuits as defined in 800.2.

Informational Note: For information on listing requirements for both information technology equipment andcommunications equipment, see UL 60950-1-2011,

.A room within the information technology equipment area that contains

the information technology equipment. [ 3.3.9]An electric device and circuit that controls a disconnecting means through a relay or

equivalent device.A physically identifiable area (such as barriers or separation by distance) within an information technology

equipment room, with dedicated power and cooling systems for the information technology equipment or systems.Circuits and equipment shall comply with 645.3(A) through (H), as applicable.

The provisions of 300.21, 770.26, 800.26, and 820.26 shall apply topenetrations of the fire-resistant room boundary.

The provisions of 300.22(C)(1), 725.154(A), 760.53(B)(2),760.154(A), 770.113(C), 800.113(C), and 820.113(C) and Tables 770.154(A), 800.154(A) and 820.154(A) shall apply tothe space over a suspended ceiling used for environmental air handling purposes in wiring and cabling in a plenum(other space used for environmental air) above an information technology equipment room.

The non–current-carrying conductive members of optical fiber cables in an information technologyequipment room shall be grounded in accordance with the provisions of 770.114.

The provisions of 725.121(A)(4) shall apply to the electrical classificationof listed information technology equipment signaling circuits. The provisions of 725.139(D)(1) and 800.133(A)(1)(b) shallapply to the electrical classification of Class 2 and Class 3 circuits in the same cable with communications circuits.

The provisions of Parts I, II, and III of Article 760 shall apply to fire alarm systemsequipment installed in an information technology equipment room.

The provisions of Parts I, II, III, IV, and V of Article 800 shall apply tocommunications equipment installed in an information technology equipment room. Article 645 shall apply to thepowering of communications equipment in an information technology equipment room.

Informational Note: See Part I of Article 100, Definitions, for a definition of communications equipment.The provisions of Parts I, II, III, IV,

and V of Article 820 shall apply to community antenna television and radio distribution systems equipment installed in an

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Report on Comments – June 2013 NFPA 70information technology equipment room. Article 645 shall apply to the powering of community antenna television andradio distribution systems equipment installed in an information technology equipment room.

Cables extending beyond the information technologyequipment room shall be subject to the applicable requirements of this .

This article shall be permitted to providealternate wiring methods within the information technology room and under the raised floor to the provisions of Chapter3 Chapters 1 through 4 for power wiring, Parts I and III of Article 725 for signaling wiring and Parts I and V of Article 770for optical fiber cabling when all of the following conditions are met:

(1) Disconnecting means complying with 645.32 645.30 are provided.(2) A heating/ventilating/air-conditioning (HVAC) system is provided in one of the methods identified in 645.4(2)(a) or

(b).(a) a separate HVAC system that is dedicated for information technology equipment use and is separated from other

areas of occupancy(b) an HVAC system that serves other occupancies and:(1) also serves the information technology equipment room; and(2) provides fire/smoke dampers at the point of penetration of the room boundary; and(3) activates the damper operation upon initiation by smoke detector alarms, by operation of the disconnecting means

required by 645.32 645.30, or both.

Informational Note: For further information, see NFPA 75-2009,, Chapter 10, 10.1, 10.1.1, 10.1.2, and 10.1.3.

(3) All information technology and communications equipment installed in the room is listed.(4) The room is occupied by, and accessible to, only those personnel needed for the maintenance and functional

operation of the installed information technology equipment.(5) The room is separated from other occupancies by fire-resistant-rated walls, floors, and ceilings with protected

openings.Informational Note: For further information on room construction requirements, see NFPA 75-2009,

, Chapter 5.(6) Only electrical equipment and wiring associated with the operation of the information technology room is installed in

the room.Informational Note: HVAC systems, communications systems, and monitoring systems such as telephone, fire alarm

systems, security systems, water detection systems, and other related protective equipment are examples of equipmentassociated with the operation of the information technology room.

(7) If a raised floor is present, the raised floor is of approved construction, and the area under the floor is accessible.(8) If a raised floor in present, ventilation in the underfloor area is used for the information technology equipment room

only, except as provided in 645.4(2). The ventilation system shall also be so arranged, with approved smoke detectiondevices, that upon the detection of fire or products of combustion in the underfloor space, the circulation of air willcease.

(9) If a raised floor is present, openings for cords and cables protect cords and cables against abrasion and minimizethe entrance of debris beneath the floor.

All exposed non–current-carrying metal parts of an informationtechnology system shall be bonded to the equipment grounding conductor in accordance with the provisions of Parts V,VI and VII of Article 250 or shall be double insulated. Where signal reference structures are installed, they shall bebonded to the equipment grounding conductor provided for the information technology equipment. Any auxiliarygrounding electrode(s) installed for information technology equipment shall be installed in accordance with theprovisions of 250.54.

Informational Note No. 1: The bonding requirements in the product standards governing this listed equipment ensurethat it complies with Article 250.

Informational Note No. 2: Where isolated grounding-type receptacles are used, see 250.146(D) and 406.3(D).Separately derived power systems shall be installed in accordance with the provisions of

Part II or Article 250. Power systems derived within listed information technology equipment that supply informationtechnology systems through receptacles or cable assemblies supplied as part of this equipment shall not be consideredseparately derived for the purpose of applying 250.30.

All exposed non–current-carrying metal parts of an information technology system shall be bonded

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Report on Comments – June 2013 NFPA 70to the equipment grounding conductor or shall be double insulated. Where signal reference structures are installed, theyshall be bonded to the equipment grounding conductor provided for the information technology equipment. Any auxiliarygrounding electrode(s) installed for information technology equipment shall be installed in accordance with Section250.54.Informational Note: The bonding requirements in the product standards governing this listed equipment ensure that itcomplies with Article 250.

As an alternative to the feeder and service load calculations required byParts III and IV of Article 220, feeder and service load calculations for new or existing loads shall be permitted to beused if provided by qualified persons under engineering supervision.

The branch-circuit conductors supplying one or more units ofinformation technology equipment shall have an ampacity not less than 125 percent of the total connected load.

Each unit of an information technology system supplied by a branch circuit shallbe provided with a manufacturer’s nameplate, which shall also include the input power requirements for voltage,frequency, and maximum rated load in amperes.

The accessible portion of abandonedsupply circuits and interconnecting cables shall be removed unless contained in a raceway.

(1) Supply circuits and interconnecting cables identified for future use shall be marked with a tag of sufficient durabilityto withstand the environment involved.

(2) Supply circuit tags and interconnecting cable tags shall have the following information:(1) a. Date identified for future use(2) b. Date of intended use(3) c. Information relating to the intended future use

Where exposed to physicaldamage, supply circuits and interconnecting cables shall be protected.

Power cables; communications cables; connecting cables; interconnecting cables;and associated boxes, connectors, plugs, and receptacles that are listed as part of, or for, information technologyequipment shall not be required to be secured in place.

Except for installations and constructions covered in645.30(1) 645.20(1) or (2), UPS systems installed within the information technology equipment room, and their supplyand output circuits, shall comply with 645.32 645.30. The disconnecting means shall also disconnect the battery from itsload.

(1) Installations qualifying under the provisions of Article 685(2) Power sources limited to 750 volt-amperes or less derived either from UPS equipment or from battery circuits

integral to electronic equipmentPower distribution units that are used for information technology equipment

shall be permitted to have multiple panelboards within a single cabinet, if the power distribution unit is utilizationequipment listed for information technology application.

Power systems derived within listed information technology equipment thatsupply information technology systems through receptacles or cable assemblies supplied as part of this equipment shallnot be considered separately derived for the purpose of applying 250.30

Informational Note: Where isolated grounding-type receptacles are used, see 250.146(D) and 406.3(D).An approved means shall be provided to disconnect power to all electronic

equipment in the information technology equipment room or in designated zones within the room. There shall also be asimilar approved means to disconnect the power to all dedicated HVAC systems serving the room or designated zonesand shall cause all required fire/smoke dampers to close. The installation of remote disconnect controls shall be inaccordance with (A) through (B).

(1) Remote disconnect means shall be located at approved locations readily accessible in case of fire to authorizedpersonnel and emergency responders.

(2) The remote disconnect controls for the control of electronic equipment power and HVAC systems shall be groupedand identified. A single means to control both systems shall be permitted.

(3) Where multiple zones are created, each zone shall have an approved means to confine fire or products ofcombustion to within the zone.

(4) Additional means to prevent unintentional operation of remote disconnect controls shall be permitted.

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Report on Comments – June 2013 NFPA 70Informational Note: For further information, see NFPA 75-2009,

Remote disconnecting controls shall not be required for critical operations datasystems when all of the following conditions are met:

(1) An approved procedure has been established and maintained for removing power and air movement within theroom or zone.

(2) Qualified personnel are continuously available to meet emergency responders and to advise them of disconnectingmethods.

(3) A smoke-sensing fire detection system is in place.Informational Note: For further information, see -2010, .(4) An approved fire suppression system suitable for the application is in place.(5) Signal wiring under a raised floor is in compliance with 645.32. Cables installed under a raised floor, other than

branch-circuit wiring and power cords are installed in compliance with 645.36(A) and 645.36(A), (B) or (C), or incompliance with 300.22(C), 725.154 (A), 770.113(C) and Table 770.154(a), 800.113(C) and Table 800.154(a), or820.113(C) and Table 820.154(a).

Critical Operations Data System(s) overcurrent devices shall be selectivelycoordinated with all supply side overcurrent protective devices.

Information technology equipment shall be permitted to be connected to abranch circuit by a power-supply cord.

(1) Power-supply cords shall not exceed 4.5 m (15 ft).(2) Power cords shall be listed and a type permitted for use on listed information technology equipment or shall be

constructed of listed flexible cord and listed attachment plugs and cord connectors of a type permitted for informationtechnology equipment.

Informational Note: One method of determining if cords are of a type permitted for the purpose is found in UL60950-1-2011 2007,

Separate information technology equipment units shall be permitted to beinterconnected by means of listed cables and cable assemblies. The 4.5 m (15 ft) limitation in 645.34(1) 645.27(1) shallnot apply to interconnecting cables.

Power cables, connecting cables, interconnecting cables, cord-and-plugconnections, and receptacles associated with the information technology equipment shall be permitted to be installedunder a raised floor shall comply with (1) through (4): provided the conditions of 645.36(A)are met. The installation ofbranch circuit conductors shall be in accordance with the provisions of 645.36(B). The installation of electrical supplycords, data cables, interconnecting cables and grounding conductors shall be in accordance with the provisions of645.36(C). The installation of optical fiber cables shall be in accordance with the provisions of 645. 36(D):

(1) The raised floor is of approved construction, and the area under the floor is accessible.(2) Ventilation in the underfloor area is used for the information technology equipment room only, except as provided in

645.4(2). The ventilation system is arranged, with approved smoke detection devices, that upon the detection of fire orproducts of combustion in the underfloor space, the circulation of air will cease.

(3) Openings in raised floors for cords and cables protect cords and cables against abrasion and minimize the entranceof debris beneath the floor.

The provisions of 300.11 shall applyThe provisions of 300.22(C) shall apply.

(1) The branch-circuit supply conductors to receptacles or field-wired equipment are in rigid metal conduit, rigidnonmetallic conduit, intermediate metal conduit, electrical metallic tubing electrical nonmetallic tubing, metal wireway,nonmetallic wireway, surface metal raceway with metal cover, surface nonmetallic raceway, flexible metal conduit,liquidtight flexible metal conduit, or liquidtight flexible nonmetallic conduit, Type MI cable, Type MC cable, or Type AC orType TC cable and associated metallic and nonmetallic boxes or enclosures. These supply conductors shall be installedin accordance with the requirements of 300.11.

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Report on Comments – June 2013 NFPA 70The following cords, cables and conductors shall be permitted to be installed under

a raised floor.(12) Supply cords of listed information technology equipment in accordance with 645.34 645.27 shall be permitted.(23) Interconnecting cables shall be enclosed in a raceway(34) Equipment grounding conductors

The following wiring cables shall be permitted:(1) Cable type designations shown in Table 645.31(24)Listed Type DP cable having adequate fire-resistant characteristics suitable for use under raised floors of an

information technology equipment room

(2) Listed interconnecting cables, enclosed in a raceway, that interconnect separate information technology equipmentunits.

Renumber Table 645.5 to 645.31(5) Cable type designations shown in Table 645.36

******Insert Table 645.36 Here******

Under Raised Floors in a Critical Operations Data System. Signal wiring under a raised floor in a criticaloperations data system shall be in compliance with 300.22(C), 725.154(A), 770.113(C) and Table 770.154(a),800.113(C) and Table 800.154(a), or 820.113(C) and Table 820.154(a).

(A) Installation Requirements for Optical Fiber Cables Under a Raised Floor. Optical fiber cables under a raised floorshall be installed in accordance with the provisions of 770.113(C) and Table 770.154(a).

Exception: Types ORNR, OFCR, OFN and OFC shall be permitted to be installed under a raised floor.This is one of several Comments prepared by the CMP 12 Article 645 Task Group consisting of CMP

12 members Tom Brown, Tim Croushore, Tom Hedges, Bob Johnson, Stan Kaufman, John Kovacik, Todd Lottmannand Jose Salazar.

The Task Group was appointed by CMP 12 Chairman Croushore to review the reorganization. In addition, the taskgroup took on the assignment of making recommendations to implement the Correlating Committee directives:

Reconsider and review the proposal in its entirety for compliance with the NEC Style Manual.Renumber so that numbering between Parts should start, at minimum, with the next decade in accordance with the

NEC Style Manual.Reconsider the titles for both Parts II and Parts III to improve clarity.Reconsidered the term “power grounding” since it is not defined in the NEC.The Task Group’s recommended text improves clarity by reorganizing Article 645 into two parts, Part I, General and

Part II, Wiring Methods. The text as proposed and accepted in principle had three parts, Part I, General, Part II, PowerCircuits and Part III, Signaling Circuits. Clarity is improved by having Part II, Wiring Methods cover both power andsignaling because some of the wring methods, DP Cable, for example, can be used for powering or signaling. Doing soalso complies with the Correlating Committee directive to reconsider the titles for Parts II and III.

The recommended text for 645.2, Definitions, restores the informational note associated with Information TechnologyEquipment. It had been inadvertently omitted from the proposal. With the restoration of the informational note, therecommended text for 645.2 is identical to the text in the 2011 NEC except that the reference to UL 60950 has beenupdated from 2007 to 2011.The recommended text for 645.3 revises the panel action by adding “the provisions of” in several more places. Seepanel action on proposals 12-110a and 12-111. The recommended text for 645.3 is in compliance with the NEC StyleManual. 645.3(B) was revised to improve clarity.

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NEC A2013/NFPA 70/ROC Log #389/Table 645.36/Rec

Table 645.5 645.36 Cable Types Permitted Under Raised Floors

Article Plenum Riser General Purpose

336 TC

725 CL2P & CL3P CL2R & CL3R CL2, CL3 & PLTC

727 ITC

760 NPLFP & FPLP NPLFR & FPLR NPLF & FPL

770 OFNP & OFCP OFNR & OFCR OFN & OFC

800 CMP CMR CM & CMG

820 CATVP CATVR CATV

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Report on Comments – June 2013 NFPA 70The recommended revision to the introductory paragraph of 645.4, which replaces “Chapters 1 through 4” with

“Chapter 3” clarifies the intent of 645.4 and reflects the titles of the Articles. The title of Chapter 1 is “General”; Chapter2, “Wiring and Protection”; Chapter 3, “Wiring Methods; and Chapter 4 “Equipment for General Use”.The intent of Article 645 is to provide “alternate wiring methods” that are commonly found in Chapter 3 of the NationalElectrical Code. Article 645 provides an option to Chapter 3 wiring methods when the facility and installation meets thequalification requirements contained within Article 645 to allow such an option. The non-wiring method requirementscontained in Article 645 do supplement or modify the requirements contained within Chapters 1, 2, and 4 of the NEC asper 90.3.

The recommended text for 645.4 deletes 645.4(7), (8) and (9) since it recommends moving these required conditionsback to the section on wiring under raised floors (645.36(A)).

The recommended text for 645.4 revises several cross-references to coordinate with the renumbering of thereferenced sections.

New Part II, Wiring Methods begins with 645.20 in compliance with the Correlating Committee directive on numbering.Part II begins with grounding and bonding and divides the grounding requirements into two logical sections, one forequipment grounding and bonding and one for systems grounding, and adds requirements for separately derived powersystems. The recommended text for 645.20, Equipment Grounding and Bonding and 645.21 System Groundingreplaces 645.15 Grounding and 645.22 Power Systems Grounding in the text accepted at the ROP meeting and therebycomplies with the Correlating committee directive to reconsider the term “power grounding”.

The recommended text for 645.20 complies with the NEC Style Manual prohibition of references to entire Articles byspecifying the relevant parts of Article 250 that should apply. The accepted text from the Panel action on Proposal12-139 continues to be included in the recommended text.

The renumbering includes reordering the sections so that the planning sections on engineering calculations (645.22Engineering supervision) and sizing of conductors (645.23 Ampacity of Branch-Circuit Conductors) are encounteredbefore the installation sections. Note that the title of 645.23 is expanded from Branch-Circuit Conductors to Ampacity ofBranch-Circuit Conductors to have the title of the section better describe the contents of the section.

Likewise, the title of the next section (645.24 Equipment Marking) has been expanded from “Marking” to reflect thatwhat this section is about, equipment marking and not circuit or cable marking.

The numbering within 645.26, Installed Supply Circuits and Interconnecting Cables Identified for Future Use, has beenrevised to comply with the NEC Style Manual. See 645.19 in the NEC ROP Preprint, where the editor made thischange.

The title of the Physical Protection section (645.27), has been expanded to Physical Protection of Supply circuits andInterconnecting Cables to accurately reflect the actual content of the section.

Other than renumbering to comply with the Correlating Committee directive, the sections on securing in place, UPSsand PDUs are unchanged. The cross-references to other sections are changed wherever necessary.

Within the renumbered section on disconnecting means (645.32), section 645.32(B)(5) on signal wiring has beenrestored to the text in 645.10(B)(5) in the 2011 NEC (with cross-references renumbered as necessary).

Section 645.33 Selective Coordination has been placed immediately after the section on disconnecting meansbecause relates to critical operations data systems, which is directly above it in the recommended text.

In 645.34 Power-Supply Cords, the reference to UL 60950 in the informational note, has been updated from 2007 to2011.

The section on Interconnecting Cables is unchanged except for the renumbering of the section and renumbering of thecross-reference to the length limitation on power-supply cords.

The text for the section on wiring under raised floors has been revised to clearly state the conditions that must besatisfied before wiring is permitted under a raised floor (645.36(A)) and installation requirements are clearly labeled asinstallation requirements.

The recommended text for 645.4 is clear that the provisions of Chapter 3 apply to power wiring and Article 645 ispermitted to provide alternate wiring methods to Chapter 3. The recommended text for the installation requirements forbranch circuit conductors under a raised floor states the two sections of Chapter 3 that apply (300.11 and 300.22(C))and then introduces the alternate wiring methods as exceptions.

The first exception covers permitted raceways and second exception covers permitted cables. Exception No. 1includes all the raceways permitted in 645.5(E)(2) but not permitted by 300.22(C)(1) in the 2011 NEC.

The text of the Exception No. 2 correlates with CMP 3 action on proposal 3-84 which added additional prohibitions onthe use of plastic jacked metal-sheathed cables in air plenums (other spaces used for environmental air). Specifically,the revision to 300.22(C)(1) permits Type MI cable without an overall nonmetallic covering, but not Type MI cable withan overall nonmetallic covering. Since Article 645 in the 2011 NEC permits Type MI cable with or without an overallnonmetallic covering, the recommended text for 645.36(B) Exception No. 2 permits plastic jacketed Type MI cable, i.e.;MI Cable with an overall nonmetallic covering.

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Report on Comments – June 2013 NFPA 70The existing text of 300.22(C)(1) in the 2011 NEC and in the accepted text for the 2014 NEC, only permits Type MC

cable without an overall nonmetallic covering, but not Type MC cable with an overall nonmetallic covering. Since Article645 in the 2011 NEC permits Type MC cable with or without an overall nonmetallic covering, the recommended text for645.36(B) Exception No. 2 permits plastic jacketed Type MC cable, i.e.; MC Cable with an overall nonmetallic covering.

The recommended text for 645.36(C) covers all the electrical cables and conductors permitted for electrical supplycords, data cables, interconnecting cables and grounding conductors. Type TC has been restored to Table 645.36(renumbered Table 645.5) because it was inadvertently omitted in the processing of proposal 12-109. Optical fibercables are deleted form Table 645.36 to avoid any possible misconception that they are substitutes for any of theelectrical cables in the table.

The recommended text for 645.36(D) follows the same style as the recommended text for branch circuit conductors(645.36(B)), calling for compliance with the appropriate sections in Article 770 and then permitting other cables byexception.

Informational Note: Text that is followed by a reference in brackets has been extracted from NFPA 75-2009,. Only editorial changes were made to the extracted text to make

it consistent with this .

This article covers equipment, power-supply wiring, equipment interconnecting wiring, and grounding ofinformation technology equipment and systems in an information technology equipment room.

Informational Note: For further information, see NFPA 75-2009,, which covers the requirements for the protection of information technology equipment and information

technology equipment areas.

Installed supply circuits and interconnecting cables that arenot terminated at equipment and not identified for future use with a tag.

An information technology equipment system that requires continuous operation forreasons of public safety, emergency management, national security, or business continuity.

Equipment and systems rated 600 volts or less, normally found in offices orother business establishments and similar environments classified as ordinary locations, that are used for creation andmanipulation of data, voice, video, and similar signals that are not communications equipment as defined in Part I ofArticle 100 and do not process communications circuits as defined in 800.2.Informational Note: For information on listing requirements for both information technology equipment andcommunications equipment, see UL 60950-1-2011,

.A room within the information technology equipment area that contains

the information technology equipment. [ 3.3.9]An electric device and circuit that controls a disconnecting means through a relay or

equivalent device.A physically identifiable area (such as barriers or separation by distance) within an information technology

equipment room, with dedicated power and cooling systems for the information technology equipment or systems.Circuits and equipment shall comply with 645.3(A) through (H), as applicable.

The provisions of 300.21, 770.26, 800.26, and 820.26 shall apply topenetrations of the fire-resistant room boundary.

The provisions of 300.22(C)(1), 725.154(A), 760.53(B)(2),760.154(A), 770.113(C), 800.113(C), and 820.113(C) and Tables 770.154(A), 800.154(A) and 820.154(A) shall apply tothe space over a suspended ceiling used for environmental air handling purposes in an information technologyequipment room.

The non–current-carrying conductive members of optical fiber cables in an information technologyequipment room shall be grounded in accordance with the provisions of 770.114.

The provisions of 725.121(A)(4) shall apply to the electrical classificationof listed information technology equipment signaling circuits. The provisions of 725.139(D)(1) and 800.133(A)(1)(b) shallapply to the electrical classification of Class 2 and Class 3 circuits in the same cable with communications circuits.

The provisions of Parts I, II, and III of Article 760 shall apply to fire alarm systemsequipment installed in an information technology equipment room.

The provisions of Parts I, II, III, IV, and V of Article 800 shall apply to

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Report on Comments – June 2013 NFPA 70communications equipment installed in an information technology equipment room. Article 645 shall apply to thepowering of communications equipment in an information technology equipment room.Informational Note: See Part I of Article 100, Definitions, for a definition of communications equipment.

The provisions of Parts I, II, III, IV,and V of Article 820 shall apply to community antenna television and radio distribution systems equipment installed in aninformation technology equipment room. Article 645 shall apply to the powering of community antenna television andradio distribution systems equipment installed in an information technology equipment room.

Cables extending beyond the information technologyequipment room shall be subject to the applicable requirements of this .

This article shall be permitted to providealternate wiring methods within the information technology room and under the raised floor to the provisions of Chapter3 for power wiring, Parts I and III of Article 725 for signaling wiring and Parts I and V of Article 770 for optical fibercabling when all of the following conditions are met:

(1) Disconnecting means complying with 645.32 are provided.(2) A heating/ventilating/air-conditioning (HVAC) system is provided in one of the methods identified in 645.4(2)(a) or

(b).(a) a separate HVAC system that is dedicated for information technology equipment use and is separated from other

areas of occupancy(b) an HVAC system that serves other occupancies and:(1) also serves the information technology equipment room; and(2) provides fire/smoke dampers at the point of penetration of the room boundary; and(3) activates the damper operation upon initiation by smoke detector alarms, by operation of the disconnecting means

required by 645.32, or both.

Informational Note: For further information, see NFPA 75-2009,, Chapter 10, 10.1, 10.1.1, 10.1.2, and 10.1.3.

(3) All information technology and communications equipment installed in the room is listed.(4) The room is occupied by, and accessible to, only those personnel needed for the maintenance and functional

operation of the installed information technology equipment.(5) The room is separated from other occupancies by fire-resistant-rated walls, floors, and ceilings with protected

openings.Informational Note: For further information on room construction requirements, see NFPA 75-2009,

, Chapter 5.(6) Only electrical equipment and wiring associated with the operation of the information technology room is installed in

the room.Informational Note: HVAC systems, communications systems, and monitoring systems such as telephone, fire alarmsystems, security systems, water detection systems, and other related protective equipment are examples of equipmentassociated with the operation of the information technology room.

All exposed non–current-carrying metal parts of an informationtechnology system shall be bonded to the equipment grounding conductor in accordance with the provisions of Parts V,VI and VII of Article 250 or shall be double insulated. Where signal reference structures are installed, they shall bebonded to the equipment grounding conductor provided for the information technology equipment. Any auxiliarygrounding electrode(s) installed for information technology equipment shall be installed in accordance with theprovisions of 250.54.


Informational Note No. 2: Where isolated grounding-type receptacles are used, see 250.146(D) and 406.3(D).Separately derived power systems shall be installed in accordance with the provisions of


As an alternative to the feeder and service load calculations required by Parts IIIand IV of Article 220, feeder and service load calculations for new or existing loads shall be permitted to be used ifprovided by qualified persons under engineering supervision.

The branch-circuit conductors supplying one or more units of

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Report on Comments – June 2013 NFPA 70information technology equipment shall have an ampacity not less than 125 percent of the total connected load.

Each unit of an information technology system supplied by a branch circuit shall beprovided with a manufacturer’s nameplate, which shall also include the input power requirements for voltage, frequency,and maximum rated load in amperes.

The accessible portion of abandoned supply circuitsand interconnecting cables shall be removed unless contained in a raceway.

(1) Supply circuits and interconnecting cables identified for future use shall be marked with a tag of sufficient durabilityto withstand the environment involved.

(2) Supply circuit tags and interconnecting cable tags shall have the following information:(1) Date identified for future use(2) Date of intended use(3) Information relating to the intended future use

Where exposed to physical damage,supply circuits and interconnecting cables shall be protected.

Power cables; communications cables; connecting cables; interconnecting cables; andassociated boxes, connectors, plugs, and receptacles that are listed as part of, or for, information technology equipmentshall not be required to be secured in place.

Except for installations and constructions covered in 645.30(1) or (2),UPS systems installed within the information technology equipment room, and their supply and output circuits, shallcomply with 645.32. The disconnecting means shall also disconnect the battery from its load.

(1) Installations qualifying under the provisions of Article 685(2) Power sources limited to 750 volt-amperes or less derived either from UPS equipment or from battery circuits

integral to electronic equipmentPower distribution units that are used for information technology equipment shall be

permitted to have multiple panelboards within a single cabinet, if the power distribution unit is utilization equipment listedfor information technology application.

An approved means shall be provided to disconnect power to all electronic equipmentin the information technology equipment room or in designated zones within the room. There shall also be a similarapproved means to disconnect the power to all dedicated HVAC systems serving the room or designated zones andshall cause all required fire/smoke dampers to close. The installation of remote disconnect controls shall be inaccordance with (A) through (B).

(1) Remote disconnect means shall be located at approved locations readily accessible in case of fire to authorizedpersonnel and emergency responders.

(2) The remote disconnect controls for the control of electronic equipment power and HVAC systems shall be groupedand identified. A single means to control both systems shall be permitted.

(3) Where multiple zones are created, each zone shall have an approved means to confine fire or products ofcombustion to within the zone.

(4) Additional means to prevent unintentional operation of remote disconnect controls shall be permitted.Informational Note: For further information, see NFPA 75-2009,

Remote disconnecting controls shall not be required for critical operations datasystems when all of the following conditions are met:

(1) An approved procedure has been established and maintained for removing power and air movement within theroom or zone.

(2) Qualified personnel are continuously available to meet emergency responders and to advise them of disconnectingmethods.

(3) A smoke-sensing fire detection system is in place.Informational Note: For further information, see -2010, .

(4) An approved fire suppression system suitable for the application is in place.(5) Cables installed under a raised floor, other than branch-circuit wiring and power cords are installed in compliance

with 645.36(A) and 645.36(A), (B) or (C), or in compliance with 300.22(C), 725.154 (A), 770.113(C) and Table770.154(a), 800.113(C) and Table 800.154(a), or 820.113(C) and Table 820.154(a).

Critical Operations Data System(s) overcurrent devices shall be selectivelycoordinated with all supply side overcurrent protective devices.

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Report on Comments – June 2013 NFPA 70Information technology equipment shall be permitted to be connected to a branch circuit

by a power-supply cord.(1) Power-supply cords shall not exceed 4.5 m (15 ft).(2) Power cords shall be listed and a type permitted for use on listed information technology equipment or shall be

constructed of listed flexible cord and listed attachment plugs and cord connectors of a type permitted for informationtechnology equipment.Informational Note: One method of determining if cords are of a type permitted for the purpose is found in UL60950-1-2011,

Separate information technology equipment units shall be permitted to beinterconnected by means of listed cables and cable assemblies. The 4.5 m (15 ft) limitation in 645.34(1) shall not applyto interconnecting cables.

Power cables, connecting cables, interconnecting cables, cord-and-plug connections,and receptacles associated with the information technology equipment shall be permitted to be installed under a raisedfloor provided the conditions of 645.36(A) are met. The installation of branch circuit conductors shall be in accordancewith the provisions of 645.36(B). The installation of electrical supply cords, data cables, interconnecting cables andgrounding conductors shall be in accordance with the provisions of 645.36(C). The installation of optical fiber cablesshall be in accordance with the provisions of 645. 36(D):

(A)(1) The raised floor is of approved construction, and the area under the floor is accessible.(2) Ventilation in the underfloor area is used for the information technology equipment room only, except as provided in

645.4(2). The ventilation system is arranged, with approved smoke detection devices, that upon the detection of fire orproducts of combustion in the underfloor space, the circulation of air will cease.

(3) Openings in raised floors for cords and cables protect cords and cables against abrasion and minimize the entranceof debris beneath the floor.

The provisions of 300.11 shall apply.The provisions of 300.22(C) shall apply.

The following cords, cables and conductors shall be permitted to be installed undera raised floor.

(1) Supply cords of listed information technology equipment in accordance with 645.34(2) Interconnecting cables enclosed in a raceway(3) Equipment grounding conductors(4) Listed Type DP cable having adequate fire-resistant characteristics suitable for use under raised floors of an

information technology equipment room

(5) Cable type designations shown in Table 645.36

******Insert Table 645.36 Here******

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NEC A2013/NFPA 70/ROC Log #389/Table 645.36/Sub

Table 645.36 Cable Types Permitted Under Raised Floors

Article Plenum Riser General Purpose

336 TC

725 CL2P & CL3P CL2R & CL3R CL2, CL3 & PLTC

727 ITC

760 NPLFP & FPLP NPLFR & FPLR NPLF & FPL

800 CMP CMR CM & CMG

820 CATVP CATVR CATV

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Report on Comments – June 2013 NFPA 70Optical fiber cables under a raised

floor shall be installed in accordance with the provisions of 770.113(C) and Table 770.154(a).

_______________________________________________________________________________________________12-57 Log #576 NEC-P12


12-109It appears that the Informational Note associated with the definition of Information Technology

Equipment (ITE) will be kept, although it is not reflected in the draft ROP. If it will be kept, a reference also should beadded to the new standard, UL 62368-1.

Informational Note: For information on listing requirements for both information technology equipment andcommunications equipment, see UL 60950-1-2007,

; or UL 62368-1-2012,


was published on February 17, 2012. This new standard will eventually replace (later this decade) both, UL 60065,Audio, Video, and Similar Electronic Apparatus-Safety Requirements, and UL 60950-1, Information TechnologyEquipment Safety - Part 1: General Requirements. In the meantime, multiple references to UL 60950-1 in the body ofthe Code should be supplemented by a reference to UL 62368-1 since similar equipment complying with, and Listed toboth standards will be installed per the Code. In fact, equipment already is being Listed to UL 62368-1.

_______________________________________________________________________________________________12-58 Log #312 NEC-P12

_______________________________________________________________________________________________Frank W. Peri, Communications Cable & Connectivity Assoc.

12-109In 645.3(B) make the following changes:

The provisions of Sections 300.22(C)(1), 725.135(B) 725.154(A), 760.53(B)(2), 760.135(B) 760.154(A),770.113(C), 800.113(C), and 820.113(C) and Tables 725.154, 760.154, 770.154(A), 800.154(A) and 820.154(A) shallapply to wiring and cabling in a plenum (other space used for environmental air) above an information technologyequipment room.

In 645.32 (645.10(B) renumbered by CMP-12 action on proposal 12-109)Signal wiring under a raised floor in a critical

operations data system shall be in compliance with 300.22(C), 725.135(B) and Table 725.154 (A), 770.113(C) andTable 770.154(a), 800.113(C) and Table 800.154(a), or 820.113(C) and Table 820.154(a).

This is a correlating comment to our comments on proposal 3-144a and 3-154a to reorganize 725.154and move the installation requirements out of 725.154 into a new section 725.135. If those comments are accepted, thereferences to 725.154(A) will need to be changed to correlate.

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12-112Change the panel action from Accept to Accept in Principle and modify the text as shown:

This article shall be permitted to provide alternate wiring methods within the information technology room and underthe raised floor to the provisions of Chapter 3 Chapters 1 through 4 for power wiring, Parts I and III of Article 725 forsignaling wiring, and Parts I and V of Article 770 for optical fiber cabling when all of the following conditions are met:

The recommended revision provides clarity and reflects the titles of the Articles. The title of Chapter 1is “General”; Chapter 2, “Wiring and Protection”; Chapter 3, “Wiring Methods; and Chapter 4 “Equipment for GeneralUse”.

The intent of Article 645 is to provide “alternate wiring methods” that are commonly found in Chapter 3 of the NationalElectrical Code. Article 645 provides an option to Chapter 3 wiring methods when the facility and installation meets thequalification requirements contained within Article 645 to allow such an option. The non-wiring method requirementscontained in Article 645 do supplement or modify the requirements contained within Chapters 1, 2, and 4 of the NEC asper 90.3.

This is one of several Comments prepared by the CMP 12 Article 645 Task Group consisting of CMP 12 membersTom Brown, Tim Croushore, Tom Hedges, Bob Johnson, Stan Kaufman, John Kovacik, Todd Lottmann and JoseSalazar.

_______________________________________________________________________________________________12-60 Log #1458 NEC-P12

_______________________________________________________________________________________________Thomas J. Wysocki, Guardian Services, Inc.

12-114Delete text as follows:

Assuming my comment on Proposal 12-109 Paragraph 645.4 (8) to delete “The ventilation systemshall also be so arranged, with approved smoke detection devices, that upon the detection of fire or products ofcombustion in the underfloor space, the circulation of air will cease.” is accepted, the proposed 645.4 (2) Exception willnot be pertinent.

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_______________________________________________________________________________________________Thomas J. Wysocki, Guardian Services, Inc.


(8) If a raised floor is present, ventilation in the underfloor area is used for the information technology equipment roomonly, except as provided in 645.4(2). The ventilation system shall also be so arranged, with approved smoke detectiondevices, that upon the detection of fire or products of combustion in the underfloor space, the circulation of air willcease.

The text indicated for deletion deals with control of air circulation within the IT room and is outside thescope of NFPA 70 and sets forth a requirement which is often technically undesirable in modern information technologyrooms.

The basis of the comment is twofold:1) Responsibility for the protection of IT facilities is the scope of NFPA 75. Within that scope NFPA 75 covers risk

considerations, construction, and operating (performance) requirements – control of airflow within an IT facility is theprovince of NFPA 75.

Acceptance of this comment would remove a conflict in requirements between NFPA 75 and NFPA 70 and clarify thedemarcation between “what” (NFPA 75) must be done in IT facilities and “how” (NFPA 70) to accomplish the electricalinstallation.

The operating characteristics (performance) of an information technology equipment room are the province of NFPA75. NFPA 70 addresses the “how” of accomplishing the functions required by NFPA 75 for operation of IT equipmentand the utilities serving the IT facility. Several decisions of the Standards Council point to the responsibility of NFPA 75with respect to control of combustible in IT facilities.

Standards Council decision 89-50 (April 1991) affirmed that the Committee on Electronic Computer Systems (NFPA75) has responsibility for combustibles under the raised floor of a computer room. NFPA 90A 2012 Edition recognizesthis fact and states the following with respect to materials installed within a raised floor plenum in a computer/dataprocessing room:

4.3.11.5.5.5 Raised floors, intermachine cables, electrical wires, listed plenum optical fiber, communications andsignaling raceways, and optical-fiber cables in computer/data processing rooms where these rooms are designed andinstalled in accordance with NFPA 75, Standard for the Protection of Information Technology Equipment, shall bepermitted. (NFPA 90A 2012 Edition)

On March 6, 2012, the NFPA Standards Council issued a TIA which removed the paragraph 10.4.4 of NFPA 75 Edition2009 which had extracted the exact verbiage of NFPA 70 645.5D(3) Edition 2005 (NFPA 70 645.5E(4) Edition 2011) ,verbiage which is now in the proposed NFPA 70 645.4(8). The NFPA 75 technical committee was clear in its intent thatcessation of airflow in the underfloor space upon detection of fire or smoke under the raised floor should not be ageneral requirement for operation of an IT facility.

2) There is no technical basis for shutting down airflow in an IT facility upon detection of smoke or fire under a raisedfloor. The original basis for adding the sentence in question was not technical – rather it was an attempt to alleviate aproblem related to application of building codes to underfloor spaces (NFPA 70 May 2001 ROP 12 – 100).

On the contrary in modern IT facilities, there is good technical basis not to shut down airflow upon detection of smokeor fire under the raised floor. In considering the technical merit of the 2012 TIA, the NFPA 75 technical committee tooknote of the following:

Today's IT servers run applications that are critical to business continuity and frequently have life safety implications.Unplanned shutdown of the IT equipment can cause loss of control over life support systems, emergency responsesystems, security systems and loss of essential data in process. Therefore, it may be undesirable – or even dangerous –to automatically shut down equipment that is not directly involved in a fire.

Modern server racks contain multiple processing units which can create a large amount of heat. If air conditioningequipment used to cool the servers is shut down, temperatures can increase by as much as 40 degrees in a matter ofminutes, potentially causing more damage than the heat of a small electronic fire. Therefore, it is desirable to maintaincooling air flow for as long as possible.

Thermal overheat devices are built in to individual servers to immediately depower overheating components in anattempt to prevent permanent damage to entire server. If a single server or single server rack is shut down by thermalprotective devices, other servers would generally remain available to maintain functionality. But if the room or areaenvironmental cooling air suddenly would cease due to initiation of a fire detector under a raised floor, all equipment in

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Report on Comments – June 2013 NFPA 70the area could shut down on thermal overload. This would cause the uncontrolled loss of all function provided by the ITequipment and this can have serious consequences.

Fire suppression systems used in IT facilities are often designed to detect and extinguish fire in its incipient stage whilecooling air flow through the facility is maintained and servers remain running. If depowering of equipment is required aspart of the fire protection, such depowering is generally done in a planned, programmed sequence to minimize loss ofdata. When an IT facility is providing support or control related to life safety or security, the depowering sequencetypically includes provision to transfersupport or control functions to a backup IT facility. Determination of when it is safe to shut off ventilation to the ITequipment is part of the planned depowering sequence.

In IT facilities protected by automatic gaseous extinguishing systems, the activation of more than one detector isusually required to confirm existence of fire and thereby release the fire extinguishing gas. Air flow is taken into accountin locating smoke detectors.

Cessation of normal air flow upon activation of a single smoke detector can delay the activation of additional smokedetectors in the IT facility and thereby delay release of automatic gaseous extinguishing agent in facilities equipped withsuch systems. The subject of airflow and its effect on fire detection in IT facilities and telecommunications facilities is thesubject of ongoing research by the FPRF with the advice of a joint task group of NFPA 75 and NFPA 76 technicalcommittee representatives. Again control of airflow is a subject for the occupancy standards rather than the NEC.

Furthermore, very recent research indicates that, for the type of fire typical in IT facilities, extinguishment may actuallybe aided by continuous flow of air through the fire zone. The airflow helps cool the fire zone and, because of the typicallysmoldering nature of these fires in their early stages, can reduce the amount of heat available to be carried byconduction to nearby materials. This is complex research to be made public shortly. The results of this research arefurther indication of the wisdom of the NFPA 75technical committee’s refusal to place a general requirement for cessation of airflow in the IT protection standard.Indeed the subject of airflow control in IT facilities is in the province and scope of the NFPA 75 technical committee, themembership of which includes persons closely involved with leading-edge IT technology and fire protection methods forsuch technology.

Upon detection of smoke or fire anywhere within the IT facility, personnel will be alerted to the danger by the fire alarmsystem. Personnel are given the opportunity for appropriate evacuation or response to the alarm. Cessation of airflowthrough the raised floor is not necessary. If personnel are not present, the features of the automatic fire protectionsystems are permitted to function per their design.

_______________________________________________________________________________________________12-62 Log #1570 NEC-P12

_______________________________________________________________________________________________Frederic P. Hartwell, Hartwell Electrical Services, Inc.

12-133Accept the proposal in principle. Revise text to read as follows:

The disconnecting means shall be implemented by comply with either (A) or (B).This wording meets the panel objection, but retains the part of the proposal that eliminates phrasing

that does not occur elsewhere in the NEC and replaces it with much more familiar and user-friendly language.

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12-109Revise the Informational Note associated with 645.27(2) to reference the new standard UL 62368-1.

Informational Note: One method of determining if cords are of a type permitted for the purpose is found in UL60950-1-2007, UL 62368-1-2012,


was published on February 17, 2012. This new standard will eventually replace (later this decade) both, UL 60065,Audio, Video, and Similar Electronic Apparatus-Safety Requirements, and UL 60950-1, Information TechnologyEquipment Safety - Part 1: General Requirements. In the meantime, multiple references to UL 60950-1 in the body ofthe Code should be supplemented by a reference to UL 62368-1 since similar equipment complying with, and Listed toboth standards will be installed per the Code. In fact, equipment already is being Listed to UL 62368-1.

_______________________________________________________________________________________________12-64 Log #172 NEC-P12


12-128The Correlating Committee directs that the panel clarify the panel action on this proposal as the

accepted revision does not appear in the panel action on Proposal 12-109.This is a direction from the National Electrical Code Technical Correlating Committee in accordance


_______________________________________________________________________________________________12-65 Log #1446 NEC-P12

_______________________________________________________________________________________________Ralph Transue, The RJA Group, Inc.

12-136Add and Article 708 after “Chapters 1 through 4”.

I submitted proposal 12-136 because some users may associate a critical operations data system withArticle 708, Critical Operations Power Systems. Applying Article 708 to a data center would apply many untenablerequirements to the data center, so many that the user would choose to opt out of Article 645. The text recommended bythis comment is based on Dr. Stanley Kaufman’s affirmative ballot statement on proposal 12-136.

_______________________________________________________________________________________________12-66 Log #173 NEC-P12


12-137The Correlating Committee directs that the panel clarify the panel action on this proposal with

respect to the location of the revised text.This is a direction from the National Electrical Code Technical Correlating Committee in accordance


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12-137Change the panel action from Accept to Accept in Principle with the Panel statement “See panel

action on Comment 12-xxx on Proposal 12-109.In the Standards Council issued errata No. 70-11-1, item 20 fixed the renumbering of 645(D)(2) and

645(D)(3), so no action is required on that part of the Proposal.The recommendation in the Proposal to improve clarity by adding the word “are” should be accepted in principle with

reference to the Panel action on the Comment submitted on Proposal 12-109 by the CMP 12 Article 645 Task Group.This is one of several Comments prepared by the CMP 12 Article 645 Task Group consisting of CMP 12 members

Tom Brown, Tim Croushore, Tom Hedges, Bob Johnson, Stan Kaufman, John Kovacik, Todd Lottmann and JoseSalazar.

_______________________________________________________________________________________________12-68 Log #388 NEC-P12


12-138Change the panel action from Accept to Accept in Principle and modify the text of 645.15 as

shown:All exposed non–current-carrying metal parts of an information

technology system shall be bonded to the equipment grounding conductor in accordance with the provisions of Parts V,VI and VII of Article 250 or shall be double insulated. Power systems derived within listed information technologyequipment that supply information technology systems through receptacles or cable assemblies supplied as part of thisequipment shall not be considered separately derived for the purpose of applying 250.30. Where signal referencestructures are installed, they shall be bonded to the equipment grounding conductor provided for the informationtechnology equipment. Any auxiliary grounding electrode(s) installed for information technology equipment shall beinstalled in accordance with the provisions of 250.54.


Informational Note No. 2: Where isolated grounding-type receptacles are used, see Sections 250.146(D) and 406.3(D).Separately derived power systems shall be installed in accordance with the provisions of


The panel action on Proposal 12-138 to delete the reference to the entire Article 250 in order tocomply with the NEC Style Manual prohibition on references to entire Articles provided less information than leaving thetext unchanged. The preferred route to complying with the NEC Style Manual prohibition on references to entire Articlesis to refer to specific Parts or sections within an Article; that’s what this Comment recommends.

The recommendation divides the grounding requirements into two logical sections, one for equipment grounding andbonding and one for systems grounding, and adds requirements for separately derived power systems

The accepted text from the Panel action on Proposal 12-139 is included in the recommended text.This is one of several Comments prepared by the CMP 12 Article 645 Task Group consisting of CMP 12 members

Tom Brown, Tim Croushore, Tom Hedges, Bob Johnson, Stan Kaufman, John Kovacik, Todd Lottmann and JoseSalazar.

The sections are renumbered to coordinate with the Task Groups’ Comment on Proposal 12-109.

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12-147The Correlating Committee advises that new articles and article scope statements are the

responsibility of the Correlating Committee and the Correlating Committee Accepts the panel action.The Correlating Committee directs that the new Article be reviewed to satisfy all NEC Style Manual requirements.


_______________________________________________________________________________________________12-70 Log #1379 NEC-P12

_______________________________________________________________________________________________Dennis R. Julian, Integrated Design Group Inc.

Delete all text in Article 646 after paragraph 64X.4.The text to be deleted mainly duplicates existing code requirements. Because it is a duplication of

many specific requirements, it is confusing and may be contradictory to requirements in the code. In some aspects it isslightly different which may lead to confusion. A modular data center should follow the same code requirements as adata center. Any specific differences should be listed in this article. Because only parts of the code are repeated, it willlead to unintended consequences. For instance, Article 645 has exceptions for EPO requirements that are not repeatedin Article 646. The requirement for EPO includes shutting down the entire MDC whether it includes raised floor areas ornot and also includes the electrical and UPS areas. Stating similar requirements in multiple locations will allow formis-interpretations and mis-applications as the two references are interchanged.

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_______________________________________________________________________________________________John R. Kovacik, UL LLC

12-147Revise the Panel Meeting Action to Accept-in–Principle, Proposal 12-147 as follows;

Informational Note: Text that is followed by a reference in brackets has been extracted from NFPA 75-2009, Standardfor the Protection of Information Technology Equipment. Only editorial changes were made to the extracted text tomake it consistent with this Code.

This article covers modular data centers.Informational Note 1: Modular data centers include the installed information technology equipment (ITE) IT and support

equipment, electrical supply and distribution, wiring and protection, working space, grounding, HVAC and the like,located in or associated with a modular data center an equipment enclosure.

Informational Note 2: For further information, see NFPA 75-20132009, Standard for the Protection of InformationTechnology Equipment, which covers the requirements for the protection of information technology equipment andsystems in an information technology equipment areas room.

The definitions in 645.2 shall apply. For the purposes of this article, the followingadditional definitions apply applies.

Prefabricated units rated 600 volts or less, consisting of an outer enclosure housingmultiple racks of information technology equipment (ITE) (e.g. servers) and various support equipment such as electricalservice and distribution equipment, HVAC systems and the like. Some configurations may have the support equipmenthoused in a separate equipment enclosure.

Informational Note 1: A typical construction may use a standard ISO shipping container or other structure as the outerenclosure, racks or cabinets of ITE, service entrance equipment and power distribution components, power storagesuch as a UPS and an air or liquid cooling system. Modular data centers are intended for fixed installation either indoorsor outdoors based on their construction and resistance to environmental conditions. MDCs can be configured as anall-in-one system housed in a single equipment enclosure or as a system with the support equipment housed inseparate equipment enclosures.

Informational Note 2: For information on listing requirements for both information technology equipment andcommunications equipment, see UL 60950-1-2007 2011, Information Technology Equipment - Safety - Part 1: GeneralRequirements and UL 62368-1-2012, Audio/video, information and communication technology equipment - Part 1:Safety requirements.

Informational Note 3: Modular Data Centers as defined in this article are sometimes referred to as Containerized DataCenters.

Informational Note 4: Equipment enclosures housing only support equipment (e.g. HVAC or power distributionequipment) that are not part of a specific Modular Data Center are not considered a modular data center as defined inthis article.

Circuits and equipment shall also comply with 646.3(A) through (N), the following, as applicable.Wherever the requirements of other articles of this Code and Article 646 differ, the requirements of Article 646 shallapply.

The provisions of Sections 300.21, 770.26, 800.26, and 820.26 shallapply to penetrations of a fire-resistant room boundary, if provided.

The provisions of Sections 300.22(C)(1), 725.154(A), 760.53(B)(2), 760.154(A), 770.113(C), 800.113(C),and 820.113(C) and Tables 725.154(a), 760.154(a),770.154(a), 800.154(a) and 820.154(a) shall apply to wiring andcabling in a plenum (other space used for environmental air). Environmentally controlled working space, aisles andequipment areas in an MDC are not considered a plenum.

Grounding and bonding of a modular data center shall comply with Article 250. Thenon–current-carrying conductive members of optical fiber cables in an MDC shall be grounded in accordance with770.114. Grounding and bonding of communications protectors, cable shields and non–current-carrying metallicmembers of cable shall comply with Part IV of Article 800.

The provisions of Section 725.121(A)(4) shall apply to the electricalclassification of listed information technology equipment signaling circuits. The provisions of Section 725.139(D)(1) and

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Report on Comments – June 2013 NFPA 70800.133(A)(1)(b) shall apply to the electrical classification of Class 2 and Class 3 circuits in the same cable withcommunications circuits.

The provisions of Pparts I, II, and III of Article 760 shall apply to fire alarm systemsequipment installed in a MDC, when provided.

The provisions of Pparts I, II, III, IV, and V of Article 800 shall apply tocommunications equipment installed in an MDC.

Informational Note: See Part I of Article 100, Definitions, for a definition of communications equipment.The provisions of Pparts I, II, III,

IV, and V of Article 820 shall apply to community antenna television and radio distribution systems equipment installedin an MDC.

Installation of storage batteries shall comply with Article 480.

(I) Where provided, surge protective devices shall be listed and labeled andinstalled in accordance with Article 285.

Lighting shall be installed in accordance with Article 410.Power distribution wiring and wiring protection within a MDC shall

comply with Article 210 for branch circuits and Article 215 for feeder circuits.

(1) Unless modified elsewhere in this article, wiring methods and materials for power distribution shall comply withChapter 3. Wiring shall be suitable for its use and installation and shall be listed and labeled.

(2) The following wiring methods shall not be permitted:a) Integrated Gas Spacer Cable: Type IGS (Article 326)b) Concealed Knob-and-Tube Wiring (Article 394)c) Messenger-Supported Wiring (Article 396)d) Open Wiring on Insulators (Article 398)e) Outdoor Overhead Conductors over 600 Volts (Article 399)(3) Wiring under raised floors. Areas under a raised floor that are constructed and used for ventilation as described in

645.5(E) shall be permitted to use the wiring methods described in 645.5(E).(4) Installation of wiring for remote-control, signaling, and power limited circuits shall comply with Part III Article 725.(5) Installation of optical fiber cables shall comply with Part V of Article 770.(6) Installation of wiring for fire alarm systems shall comply with Parts II and III of Article 760.(7) Installation of communications wires and cables, raceways, and cable routing assemblies shall comply with Part V

of Article Chapter 800.(8) Alternate wiring methods as permitted by Article 645 shall be are permitted for MDCs provided all of the conditions

stated in 645.4 are met.For an MDC that is designed such that it may be powered from a separate electrical service,

the service equipment for control and protection of services and their installation shall comply with Article 230. Theservice equipment and their arrangement and installation shall permit the installation of the service entrance conductorsin accordance with Article 230. Service equipment shall be listed and labeled and marked as being suitable for use asservice equipment.

An approved means shall be provided to disconnect power to all electronic equipment inthe MDC in accordance with Section 645.10. There shall also be a similar approved means to disconnect the power toall dedicated HVAC systems serving the MDC and shall cause all required fire/smoke dampers to close.

All modular data centers shall:(A) (1) Bbe listed and labeled and comply with 646.3(N) and 646.5 through 646.9, or,Informational Note: One way to determine applicable listing requirements is to refer to UL Subject 2755, Outline of

Investigation for Modular Data Centers.(B) (2) Ccomply with the provisions of this article.

A permanent nameplate shall be attached to the each equipment enclosure of an MDC andshall be plainly visible after installation. The nameplate shall include the following information in 646.5(1) through (6), asapplicable:

(1) Supply voltage, number of phases, frequency, and full load current. The full-load current shown on the nameplateshall not be less than the sum of the full-load currents required for all motors and other equipment that may be inoperation at the same time under normal conditions of use. Where unusual type loads, duty cycles, and so forth requireoversized conductors or permit reduced-size conductors, the required capacity shall be included in the marked full-load

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Report on Comments – June 2013 NFPA 70current. Where more than one incoming supply circuit is to be provided, the nameplate shall state the precedinginformation for each circuit.

Informational Note 1: See 430.22(E) and 430.26 for duty cycle requirements.Informational Note 2: For listed equipment, the full-load current shown on the nameplate may be the maximum

measured, 15 minute, average full load current.(2) For MDCs powered by a separate service, the Sshort-circuit current rating of the service equipment provided as

part of the MDC.Informational Note: This rating may be part of the service equipment marking.(3) For MDCs powered by a separate service, if the required service as determined by Parts III and IV of Article 220 is

less than the rating of the service panel used, the required service shall be included on the nameplate.Informational Note: Branch circuits supplying ITE loads are assumed to be loaded no less than 80% of the branch

circuit rating with a 100% duty cycle. As an alternative to the feeder and service load calculations required by Parts IIIand IV of Article 220, feeder and service load calculations for new, future or existing loads shall be may be permitted tobe used if performed by qualified persons under engineering supervision.

(4) Electrical diagram number(s) or the number of the index to the electrical drawings.(5) For MDC equipment enclosures that are not powered by a separate service, feeder or branch circuit, a reference to

the powering equipment.(6) The manufacturer’s name or trademark

The size of the supply conductor shall be such as to have an ampacity not less than 125 percent of the fullload current rating. of all resistance heating loads plus 125 percent of the full-load current rating of the highest ratedmotor plus the sum of the full-load current ratings of all other connected motors and apparatus, based on their dutycycle, that may be in operation at the same time.

Informational Note No. 1: See the 0–2000-volt ampacity tables of Article 310 for ampacity of conductors rated 600 voltsand below.

Informational Note No. 2: See 430.22(E) and 430.26 for duty cycle requirements.Where overcurrent protection for supply conductors is furnished as part of the MDC,

overcurrent protection for each supply circuit shall comply with 646.6(B)(1) through (B)(2):Service conductors shall be provided with overcurrent protection in

accordance with 230.90 through 230.95.Where overcurrent protection for supply conductors is furnished as part of the MDC as

permitted by 240.21, the overcurrent protection shall comply with the following:(1) The overcurrent protection shall consist of a single circuit breaker or set of fuses.(2) The MDC shall be marked “overcurrent protection provided at MDC supply terminals”.(3) and tThe supply conductors shall be considered either as feeders or as taps as covered by 240.21 and be provided

with overcurrent protection complying with 240.21.The rating or setting of the overcurrent protective device for the circuit supplying the MDC shall not be greater than 125

percent of the full-load current rating. the sum of the largest rating or setting of the branch-circuit short-circuit andground-fault protective device provided with the machine, plus 125 percent of the full-load current rating of all resistanceheating loads, plus the sum of the full-load currents of all other motors and apparatus that could be in operation at thesame time.

Where no branch-circuit short-circuit and ground-fault protective device is provided with the MDC, the rating or settingof the overcurrent protective device shall be based on 430.52 and 430.53, as applicable.

Modular data centers shall not be installed where the available fault currentexceeds its short-circuit current rating as marked on the MDC service equipment.

Service equipment of a modular data center that connects directly to a service shall have ashort-circuit current rating not less than the available fault current of the service.

Modular Data Centers that connect to a branch circuit or afeeder circuit shall have a short-circuit current rating not less than the available fault current of the branch circuit orfeeder. The short circuit current rating of the MDC shall be based on the short-circuit current rating of a listed andlabeled MDC or the short-circuit current rating established utilizing an approved method.

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Report on Comments – June 2013 NFPA 70Informational Note 1: UL 508A-2001, Standard for Industrial Control Panels, Supplement SB, is an example of an

approved method.Informational Note 2: This requirement does not apply to listed and labeled equipment connected to branch circuits

located inside of the MDC equipment enclosure.(C) MDCs Powered from Separate MDC System Enclosures Connected to Power Modules. Modular Data Centers

equipment enclosures that are powered from a separate MDC system enclosure connect to a power module that is partof the specific MDC system, shall have a short-circuit current rating coordinated with the powering module inaccordance with 110.10. not less than the available fault current at the output of the power module. The short circuitcurrent rating of the MDC shall be based on the short-circuit current rating of a listed and labeled MDC or theshort-circuit current rating established utilizing an approved method.

Informational Note: UL 508A-2001, Standard for Industrial Control Panels, Supplement SB, is an example of anapproved method for determining short circuit current ratings.

A field-wiring compartment in which service or branch circuit connections are to bemade shall comply with 646.8 (A) through (C):

a) (A) Permit the connection of the supply wires after the MDC is installed;b) (B) Permit the connection to be introduced and connected easily; andc) (C) Be located so that the connections may be readily inspected after the MDC is installed

Flexible power cords and cables shall be permitted to be used for connections betweenequipment enclosures of an MDC system. Flexible cords or cables shall not be used for connection to the branch circuitor electrical service where not subject to physical damage.

Informational Note: For One example of flexible power cords usage for connections between equipment enclosures ofan MDC system is may be used between an MDC enclosure containing only servers and one containing powerdistribution equipment.

Flexible power cords or and cables shall not be used for connection to external sources ofpower.

Informational Note: Examples of external sources of power are electrical services, feeders and premises branchcircuits.

Where flexible power cords or cables are used, they shall be listed as suitable for extra-hard usage.Where used outdoors, flexible power cords and cables shall

also be listed as suitable for wet locations and shall be sunlight resistant. Extra-hard usage flexible cords or cablesshall be permitted for use as permanent wiring between MDC enclosures only where not subject to physical damage.

Single-conductor power cable shall be permitted to be used only in sizes 2 AWG orlarger.

Equipment used for the electrical supply and distribution in a modular datacenter including fittings, devices, luminaires, apparatus, machinery, and the like shall comply with the appropriaterequirements for its use and installation and shall be listed and labeled Parts I and II of Article 110.

Premise transformers installed in the MDC area shall be of the dry type or type filledwith a noncombustible dielectric medium.

Service entrance transformers shall not be permitted in an MDC.

Service entrance Utility-owned distribution transformers shall not be permitted in anMDC.

Non-utility-owned Ppremises distribution transformers installed in thevicinity of an MDC shall be of the dry type or type filled with a noncombustible dielectric medium. Such transformersshall be installed in accordance with the requirements of Article 450. Non-utility-owned Ppremises distributiontransformers shall not be permitted in an MDC.

Power transformers that supply power only to the MDC shall be permitted to be installed inthe MDC equipment enclosure. Only dry-type transformers shall be permitted to be installed in the MDC equipmentenclosure. Such transformers shall be installed in accordance with the requirements of Article 450.

At least one 125 volt AC, 15 or 20-ampere rated duplex convenience outlet shall be providedin each work area of the MDC to facilitate the connection powering of test and measurement equipment that may berequired during routine maintenance and servicing without having to route flexible power cords through or acrossdoorways, around line-ups of equipment or the like.

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Report on Comments – June 2013 NFPA 70Electrical equipment that is an integral part of the MDC including lighting,

control, power, HVAC (heating, ventilation and air-conditioning), emergency lighting, alarm circuits, and the like shallcomply with the appropriate requirements for its use and installation and shall be listed and labeled.

Listed and labeled equipment shall be installed and used in accordance with anyinstructions or limitations included in the listing.

Illumination shall be provided for all workspaces. and Aareas that are used for exitaccess and exit discharge. shall be illuminated to values of at least 1 ft.-candle (10.8 lux), measured at the floor.Theillumination shall be arranged so that the failure of any single lighting unit does not result in an a complete loss ofillumination level of less than 0.2 ft.-candle (2.2 lux).

Informational Note: See NFPA 101-2009, Life Safety Code, Section 7.8 for information on illumination of means ofegress.

Areas that are used for exit access and exit discharge shall be provided withemergency lighting. Emergency lighting systems shall be listed and labeled equipment, installed in accordance with themanufacturer’s instructions.

Informational Note: See NFPA 101-2009, Life Safety Code, Section 7.9 for information on emergency lighting.No appliances and no lamps, other than those specified as required for

emergency use, shall be supplied by emergency lighting circuits. These branch circuits supplying emergency lightingshall be installed to provide service from storage batteries, generator set, UPS, separate service, fuel cell or unitequipment. No other equipment shall be connected to these circuits, unless the emergency lighting system includes aback-up system, where only the lighting is supplied by battery circuits under power failure conditions. All boxes andenclosures (including transfer switches, generators, and power panels) for emergency circuits shall be marked toidentify them as components of an emergency circuit or system.

Access and working space shall be provided and maintained about all electrical equipment topermit ready and safe operation and maintenance of such equipment. Space about electrical equipment shall complywith 110.26. The egress requirements for large equipment in 110.26(C)(2) and personnel door requirements in110.26(C)(3) shall apply to an MDC even if the rating of the MDC is not 1200 amperes or more or if the MDC does notcontain overcurrent devices, switching devices or control devices in areas that service personnel may occupy.

Exception - The depth of the workspace shall not be required to need not comply with Table 110.26(A)(1) if theequipment is marked “WARNING” and “De-energize Equipment before Servicing” or the equivalent.

For equipment over 1.8 m (6 ft) wide or deep, there shall beone entrance to and egress from the required working space not less than 610 mm (24 in.) wide and 2.0 m (61⁄2 ft) highat each end of the working space. The door(s) shall open in the direction of egress and be equipped with panic bars,pressure plates, or other devices that are normally latched but open under simple pressure. A single entrance to andegress from the required working space shall be permitted where either of the conditions in 646.20(1) or 646.20(2) ismet.

(1) Unobstructed Egress. Where the location permits a continuous and unobstructed way of egress travel, a singleentrance to the working space shall be permitted.

(2) Extra Working Space. Where the depth of the working space is twice that required by 110.26(A)(1), a singleentrance shall be permitted. It shall be located such that the distance from the equipment to the nearest edge of theentrance is not less than the minimum clear distance specified in Table 110.26(A)(1) for equipment operating at thatvoltage and in that condition.

The working space depth in front of about ITE where any live parts that may be exposedduring routine servicing operate at not greater than 30 volts rms, 42 volts peak, or 60 volts dc shall not be required tocomply with the workspace requirements of 646.19.

Any areas of ITE that require servicing of parts that are greater than 30 volts rms, 42 volts peak, or60 volts dc shall comply with the workspace requirements of 646.19.

Informational Note 1: For example, field wiring compartments for ac mains connections, power distribution units, andthe like.

Informational Note 2: it is assumed that ITE operates at voltages not exceeding 600 V.Working space around a battery system shall comply with

paragraph 110.26. Working clearance shall be measured from the edge of the battery rack.Adequate wWork. space shall be provided for to facilitate

routine servicing and maintenance (those tasks involving operations which can safely be accomplished by employeesand where extensive disassembly of equipment is not required). Routine servicing and maintenance shall be able to be

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Report on Comments – June 2013 NFPA 70performed without exposing the worker to a risk of electric shock or personal injury.

Informational Note: An example of such routine maintenance is cleaning or replacing an air filter.

This comment was prepared by a CMP-12 Task Group that was formed to address concernspertaining to Proposal 12-147.

The Task Group including the following members:Task Group - Chair: John KovacikMembers: Tim Croushore, Jeff Holmes, Philip Clark, Todd Konieczny, Jeff Menig, Bob Johnson, Ken White, Stan

Kaufman, Steve McCluer and Randy Ivans.The following changes were made to the Panel Meeting Action to Accept-in-Principle, Proposal 12-147. These

changes take into account all of the comments expressed in the ROP balloting and comments from task groupmembers. The revisions are organized by Sections of the Article. Section numbers below are from the original ROPproposal.

The opening note was deleted since there are no such references in this proposed Article.646.1 ScopeRevised to help differentiate between an MDC as covered by this article (equipment in an enclosure) and a traditional

computer room. Also updated the reference.646.2 Definitions - Modular Data Center (MDC)Revised and added information to help clarify what an MDC, as covered by this article, really is. Updated references.646.3Clarification information added and editorial corrections646.4Added a reference to appropriate requirements for the listing of MDCs. This standard was not published at the time of

the original proposal.646.5Revised to make it clear that each equipment enclosure needs a nameplate. Added information on measuring full load

current. Added required information relating to how an equipment enclosure that is not connected to a service, feeder orbranch circuit receives its power.

646.6Revised for clarity. Added a provision for service conductors since an MDC might be provided with service equipment.

It was determined that overcurrent protection provisions could be referenced directly to 230.90-230.95 for serviceconductors and 240.21 for taps and feeders. It is intended to make sure the overcurrent protection provided in the MDCis suitable to protect the feeder or tap conductors.

646.7This was split up to cover connections directly to a service, connection to a feeder or branch circuit and connection to a

power module that is part of the MDC system. The short circuit ratings requirements for feeders and branch circuits aretaken from NFPA 70, 409.110(4). An MDC enclosure that is powered from another MDC enclosure in the system (suchas a system with an ITE module enclosure being powered from a separate power module enclosure) would not require ashort circuit current rating since it does not connect directly to a service, feeder or branch circuit. Overcurrent and shortcircuit protection would be coordinated between the two modules. 110.10 addresses this and is referenced.

646.8Editorial corrections.646.9Edited for clarity.646.10Parts I and II of Article 110 provide the necessary guidance on requirements for equipment and installations. Edited to

eliminate possible conflicts with the NEC style manual regarding possibly vague or unenforceable terms.646.11 and original 646.12Edited for clarity and combined into one section. This revision clarifies the requirements for transformers in and around

an MDC. The original 646.12 was eliminated as part of this revision.646.13Renumbered to 646.12. “Work Area” is used throughout the NEC and Life Safety Code without definition. Additional

explanatory text was added for clarity.646.14Renumbered to 646.13. Edited to eliminate possible conflicts with the NEC style manual regarding possibly vague or

unenforceable terms.646.15

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Report on Comments – June 2013 NFPA 70Renumbered to 646.14.646.16Renumbered to 646.15.Took out illumination level requirements and added informational note referencing NFPA 101.646.17Renumbered to 646.16. Took out illumination level requirements and added informational note referencing NFPA 101.646.18Renumbered to 646.17.646.19Renumbered to 646.18. Eliminated exception. Revised for clarity. Split out egress requirements. Took out reference to

110.26 for egress requirements and added appropriate text from 110.26 (B) and (C) into a new paragraph nownumbered 646.19.

646.20.Edited for clarity and editorial corrections646.21No changes.646.22Edited to eliminate possible conflicts with the NEC style manual regarding possibly vague or unenforceable terms.

_______________________________________________________________________________________________12-72 Log #485 NEC-P12



See Article 100. The definitions in 645.2 shall apply. For the purposes of this article, the followingadditional definitions apply.

Prefabricated units rated 600 volts or less, consisting of an outer enclosure housinginformation technology equipment (ITE) and various support equipment such as electrical service and distributionequipment, HVAC systems and the like. Some configurations may have the support equipment housed in a separateenclosure.Informational Note 1: A typical construction may use a standard ISO shipping container or other structure as the outerenclosure, racks or cabinets of ITE, service entrance equipment and power distribution components, power storagesuch as a UPS and an air or liquid cooling system. Modular data centers are intended for fixed installation either indoorsor outdoors based on their construction and resistance to environmental conditions.Informational Note 2: Some modular data center configurations may have the support equipment housed in a separateenclosure.Informational Note 3: For information on listing requirements for both information technology equipment andcommunications equipment, see UL 60950-1-2007,

.The second sentence in this definition is clearly a piece of non-enforceable information and is best

placed in an Informational Note. I understand that the NEC Manual of Style does not require definitions to be in singlesentences but it also requires conciseness and it is best to include any additional information not intended for actualcode use in such informational notes.If the CMP believes that this information needs to be part of the definition, it might want to revise the definition, forexample as follows:

Prefabricated units rated 600 volts or less, consisting of an outer enclosure housinginformation technology equipment (ITE) and various support equipment such as electrical service and distributionequipment, HVAC systems and the like, which are potentially housed in a separate enclosure,.

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12-147

A transformer that is fed by premises wiring.A transformer that feeds the service equipment.

646.2, 646.11, & 646.12: The premises and service entrance transformers are new, undefined terms.

_______________________________________________________________________________________________12-74 Log #606 NEC-P12


12-147.A field-wiring compartment in which service or feeder branch

circuit connections are to be made shall be readily accessible.:(1) Permit the connection of the supply wires after the MDC is installed;(2) Permit the connection to be introduced and connected easily; and(3) Be located so that the connections may be readily inspected after the MDC is installed

646.8 Typos delete extra period, delete the colon following . I believe the size of these MDCs issuch that they will be fed from feeders or services. I believe that – internally – they will have branch circuit OCPDs.

_______________________________________________________________________________________________12-75 Log #607 NEC-P12


12-147

Flexible cable shall be permitted to be used for connections between enclosures of a MDC system. Flexible cords orcables shall not be used for connection to the branch circuit or electrical service. the external (not from another MDC)power feed.

646.9 I believe the size of these MDCs is such that they will be fed from feeders or services. I believethat – internally – they will have branch circuit OCPDs.

_______________________________________________________________________________________________12-76 Log #608 NEC-P12


12-147Premise transformers installed in the MDC area shall be of the dry

type or type filled with a noncombustible dielectric medium.646.2, 646.11, & 646.12: The and are new, undefined terms.

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Access and working space shall be provided and maintained about all electrical equipment to permitready and safe operation and maintenance of such equipment. Space about electrical equipment shall comply with110.26 110.27. The egress requirements for large equipmentin 110.26 110.27 (C)(2) and personnel door requirements in 110.26 110.27 (C)(3) shall apply to an MDC even if therating of the MDC is not 1200 amperes or more or if the MDC does not contain overcurrent devices, switching devices orcontrol devices in areas that service personnel may occupy.

110.26 has been moved to110.27.

110.26 has been moved to 110.27.

_______________________________________________________________________________________________12-78 Log #609 NEC-P12


12-147

“646.19 <except>: The note refers to a non-existing paragraph. The standard way of defining labels and

signs should be used. I have serious doubts that such a warning label will be heeded in the high pressure 24/365environment these MDCs are used in.

_______________________________________________________________________________________________12-79 Log #610 NEC-P12


12-147

The working space depth in front of ITE where any live parts that may be exposed during routine servicing operateat not greater than 30 volts rms, 42 volts peak, or 60 volts dc; with a fault current less than 200 Amperes shall not berequired to comply with 646.19.

Any areas of ITE that require servicing of parts that are greater than 30 volts rms, 42 volts peak, or 60 volts dc; orwith a fault current of 200 Amperes or more shall comply with the workspace requirements of 646.19.

646.20: The “safe” voltages in this section should also and safe amperages. I have no direct informationabout safe amperages but I have worked on ITE that had low voltage high amperage uninsulated bus bars. Because ofthe increased efficiencies of DC distribution and reduced cooling requirements, I believe it will become more prevalent inthe future. See, for example:http://hightech.lbl.gov/documents/data_centers/CEC-TB-40.pdf

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Working space around a battery system shall comply with paragraph 110.26 110.27. Working clearance shall bemeasured from the edge of the battery rack.

110.26 has been moved to 110.27.

_______________________________________________________________________________________________12-81 Log #384 NEC-P12

_______________________________________________________________________________________________Jeffrey L. Holmes, IBEW Local Union 1 JATC

Delete exception entirely.Working space is truly a safety requirement and should never be disregarded for convenience or to

save money. These installations will need to be maintained, adjusted or components replaced. Ignoring worker safetyshould not be condoned.

_______________________________________________________________________________________________12-82 Log #426 NEC-P12

_______________________________________________________________________________________________Robert A. Jones, Independent Electrical Contractors, Inc.

12-147Delete the following text:

Adequate work space shall be provided for minor servicing and maintenance (those tasks involving operations whichcan be safely accomplished by employees and where extensive disassembly of equipment is not required). Minorservicing and maintenance shall be able to be performed without exposing the worker to a risk of electric shock orpersonal injury.

This requirement is unenforceable. The NEC Style Manual lists “adequate” as a possibly unenforceableand vague term in Table 3.2.1. “Minor servicing and maintenance” is not defined. Checking for proper voltage willexpose the worker to a risk of electrical shock.

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_______________________________________________________________________________________________Robert A. Jones, Independent Electrical Contractors, Inc.


Space about electrical equipment shall comply with 110.26. Section 110.26(C) shall apply to an MDC regardless ofthe ampere rating of the MDC.

“WARNING” and “De-energize Equipment before Servicing” or the equivalent.

Section 110.26 is intended to provide enough space for personnel to perform work without jeopardizingworker safety. NFPA 70E Article 130 details work involving electrical hazards and it recognizes that work may need tobe performed while energized. In order to test a branch circuit for voltage or proper voltage, the equipment will have tobe energized. Even with the proper PPE for the task the worker is still at risk of injury. Proper working space is crucialfor the safety of the worker and this cannot be compromised.

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_______________________________________________________________________________________________Martin Reid, Golden Era Productions

My comment is Article 647 should be deleted completely so as to allow 60/120V system to beuniversally used for the purpose of drastically increasing the level of electrical safety -- particularly in locations wherethere are children who would otherwise come into contact with 120VAC. 60/120VAC system should be widely used,so that children and adults making accidental contact with household and office branch circuits receive only 60V shocksinstead of 120V. Furthermore, as currently required in Article 647, 60/120V systems could be mandated to have GFCIprotection. The combination of 60/120V distribution and two-pole GFCI branch circuit breaker protection feeding suchbranch circuits would mostly close the door on accidental electrocutions in residential and office occupancies whereveremployed.

It is my understanding that 60/120V system is relegated only for sensitive electronic equipment instead of generallyallowed solely because of lamp screw-shell s being energized at 60V with the 60/120V “balanced power” system. Thisis wrong-headed because the combination of 60/120V systems with two-pole standard 7 milliamp trip GFCI circuitbreakers would basically close-the-door on residential and workplace electrocutions in the United States regardless ofthe “screw shell problem”. It is well known that most electrocutions take place on 120V 60 Hertz standard branchcircuits due to the sheer number of accidental contacts which take place.

Article 647 restricts use of 60/120V system with GFCIed branch circuits only for sensitive electronicequipment, yet the mandate and purpose is stated to be: “Committee Scope This Committee shall have primaryresponsibility for documents on minimizing the risk of electricity as a source of electric shock and as a potential ignitionsource of fires and explosions.” Article 647 has blocked drastic and revolutionary increase in electrical safety for theentire US and parts of the world by prohibiting this much-safer electrical distribution method from being used generally.It is my contention this Article was formed due to interference with the purpose of the NEC and your committee, byentrepreneurial vested interests whose aim was to market products aimed for sound-studio use having nothingwhatsoever to do with “minimizing the risk of electricity as a source of electric shock.” The purpose was to develop amarket for selling special “sensitive electronic equipment” power distribution equipment. I contend the entire reasonArticle 647 was developed was 100% entrepreneurial and 0% for the above altruistic Committee Scope and purpose.Thus, the actual exerted PURPOSE did not align with the purpose of your committee or your organization.

The PROBLEM: It is well known by most educated members of the Electrical Industry that 60 Hertz 120 volts andabove were a very poor choice for electrical safety due to peaked ventricular fibrillation risk at this voltage and aboveand at this particular frequency. Serious students of electrical shock phenomena all must ask themselves the question:HOW DID WE END UP WITH PERHAPS THE WORST POSSIBLE FREQUENCY FOR HEART FIBRILLATION as thecurrent United States standard? The answer is, it was entirely inadvertent and intended to reduce lamp flicker. It isgenerally well known that as AC voltage magnitude goes down from 120V 60 Hertz, and the closer it gets to 50V 60Hertz, the more precipitous the drop in danger of heart fibrillation. At 60VAC, the heart fibrillation risk is almost nil, andbecomes for all intents and purposes zero at 50VAC. The problem is the fact that this hazard need not be theregenerally. At all.

GFCIs are decades-old technology well proven to save lives. Had GFCIs been required for all general-use branchcircuits, many lives, including the lives of innocent children would have been saved in the last 50 years. The lives ofspecific children would have been saved I know for an absolute fact – including one specific case I heard about fromformer Riverside County Chief Electrical Inspector. The combination of 60V-to-ground systems and double-pole 7milliamp trip standard GFCI circuit breakers forms an unbeatable combination for preventing fatal electric shock inresidences and offices. Those enjoying a drastically increased electrical safety-level in the United States are only thesound studio engineers in certain sound studios, and only they have benefited from this simple distribution type. Thisdrastically increased safety must be broadened to include the next generations, so that innocents don’t end up with theirlives unnecessarily cut short. SPECIFIC REASON: My reasoning is connected with a valuation of human life. Thequestion NFPA members must ask is, what is the value of a single human life? The answer to that question isimpossible to answer, but approaches the infinite for a variety of reasons. Every single child deserves the chance toachieve greatness and a long, prosperous life filled with happiness, and their lives must not be allowed to be ever cutshort due to a silly inadvertent bad decision --- the 60 Hertz operating frequency decision combined with 120V orgreater. We in the electrical industry are charged with the responsibility to DO SOMETHING ABOUT IT.The contention has been that “general use equipment can’t handle balanced power” and that “screw shells would beenergized by 60VAC”. Are these considerations sufficient to warrant unnecessary exposure of risk to individuals? A

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Report on Comments – June 2013 NFPA 70child contacting 60VAC with 6 milliamp GFCI protection from the circuit breaker is protected. An adult inadvertentlycontacting the branch circuit is protected. 99.9% of all utilization equipment intended for 120V 60 Hertz operation willplug in to “balanced power” system without the slightest hazard. The cost of upgrading or building a facility with60/120V power is very low, as it involves a dry type transformer installed to feed the general-use branch circuits of thestructure. For those choosing to essentially close-the-door in electric shock fatalities for the most part in theirresidences or workplaces, the cost is not major particularly if undertaken as part of the original construction and designof a building. Many would be happy to bear the small additional percentage cost if they knew they were securing asafety advantage enjoyed only by a few sound engineers currently. Eventually, the consideration of the valuation ofhuman life could evolve into universal application of 60/120V system, even in Japan where it would be an even-safer50/100V. Consideration about contacts with screw-shells should not stop a quantum-leap in electrical safety fromtaking place. That consideration can be dealt with easily – not so the inherent situation with 60 Hertz operatingfrequency which we are STUCK WITH. Equipment can be tested for being usable on balanced power, and it will befound 99.9% is suitable. For the sake of future generations the other .01 per cent can be dealt with.

I am asking you to honestly and carefully consider this comment. I am aware it has ramifications, but it would alsopromote business in that those wishing to upgrade the safety of their residences for the sake of their children’s welfarewould definitely pay for the necessary dry type transformers and double-pole GFCI breakers and additional panelboardto facilitate having highly upgraded safety . Sound Engineers could continue to be protected and safe, but we shouldrevise the Code so that the same level of superlative safety can be expanded for all other uses, particularly for generaluse branch circuits which offer the highest percentage of accidental contacts that citizens make with our archaicelectrical distribution system.

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12-153Revise text to read as follows: That part of the heating equipment that converts input mechanical or electrical energy to the

voltage, current, and frequency used for the heating applicator. A converting device consists of equipment using mainsfrequency, all static multipliers, oscillator-type units using vacuum tubes, inverters using solid-state devices, or motorgenerator equipment.

A converting device shall consist of equipment using mains frequency, all static multipliers, oscillator-type unitsusing vacuum tubes, inverters using solid-state devices, or motor generator equipment.

I accept the concept that NEC definitions are not required to be in single sentences. However thisdefinition contains a list of examples and such examples are not usually contained in definitions but as information. If,on the other hand, the CMP believes that this list is a requirement it should place it somewhere else in Article 665, forexample as a section 665.3 or a similar new location, since NEC definitions shall not contain requirements. Moreover,the NEC manual of style does not permit the definition to contain the defined term and the second sentence contains thedefined term “converting device”.The NEC Manual of Style states as follows:

Definitions. Definitions shall be in alphabetical order and shall not contain the term that is being defined.Definitions shall not contain requirements or recommendations.Suggested informational note as alternative:

: A converting device consists of equipment using mains frequency, all static multipliers,oscillator-type units using vacuum tubes, inverters using solid-state devices, or motor generator equipment.

_______________________________________________________________________________________________12-87 Log #616 NEC-P12


12-153

That part of the heating equipment that converts input mechanical or electrical energy to thevoltage, current, and frequency used for the heating applicator. A converting device consists of equipment using mainsline frequency, all static multipliers, oscillator-type units using vacuum tubes, inverters using solid-state devices, ormotor generator equipment.

is British English. is American English. is used inseveral places in the Code. For instance:

This article covers the construction and installation of dielectric heating, induction heating, inductionmelting, and induction welding equipment and accessories for industrial and scientific applications. Medical or dentalapplications, appliances, or pipeline and vessel heating are not covered in this article.Use the same name for the same thing to reduce confusion.

_______________________________________________________________________________________________12-88 Log #175 NEC-P12


12-154The Correlating Committee directs that the panel clarify the panel action on this proposal.


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12-158The Correlating Committee directs that the panel correlate this proposal with the action taken on

Proposal 1-114.This is a direction from the National Electrical Code Technical Correlating Committee in accordance


_______________________________________________________________________________________________12-90 Log #487 NEC-P12



As applied to this article, a term that includes, but is not limited to,auxiliary tanks; process piping; ductwork; structural supports; exposed cell line conductors; conduits and otherraceways; pumps, positioning equipment, and cell cutout or bypass electrical devices. Auxiliary equipment includestools, welding machines, crucibles, and other portable equipment used for operation and maintenance within theelectrolytic cell line working zone.In the cell line working zone, auxiliary equipment includes the exposed conductivesurfaces of ungrounded cranes and crane-mounted cell-servicing equipment.

Equipment for use in electroplating processes shall be identified for such use.Auxiliary equipment includes tools, welding machines, crucibles, and other portable equipment used for

operation and maintenance within the electrolytic cell line working zone.In the cell line working zone, auxiliary equipment includes the exposed conductive surfaces of ungrounded

cranes and crane-mounted cell-servicing equipment.I accept the concept that NEC definitions are not required to be in single sentences. However this

definition contains a list of examples and such examples are not usually contained in definitions but as information. If,on the other hand, the CMP believes that this list is a requirement it should place it somewhere else in Article 665, forexample as a section 669.3 or a similar new location, since NEC definitions shall not contain requirements. Moreover,the NEC manual of style does not permit the definition to contain the defined term.The NEC Manual of Style states as follows:

Definitions. Definitions shall be in alphabetical order and shall not contain the term that is being defined.Definitions shall not contain requirements or recommendations.Suggested informational notes as an alternative:

: Auxiliary equipment includes tools, welding machines, crucibles, and other portable equipmentused for operation and maintenance within the electrolytic cell line working zone. In the cell lineworking zone, auxiliary equipment includes the exposed conductive surfaces of ungrounded cranes and crane-mountedcell-servicing equipment.

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The size of the supply conductor shall be such as to have an ampacity not less than 125 percent of thefull-load current rating of all resistance heating loads plus 125 percent of the full-load current rating of the highest ratedmotor plus the sum of the full-load current ratings of all other connected motors and apparatus, based on their dutycycle, that may be in operation at the same time.Informational Note No. 1: See the 0–2000-volt ampacity tables of Article 310 310.15(B)(16) through (20) for ampacity ofconductors rated 1000 volts and below.

Add a little more information to the informational note.

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