C&I Commissioning 001

8/10/2019 C&I Commissioning 001

1/17

Plant

1PMI Revision 01


2/17

Commissioning : Process by which an equipment, facility, or plant(which is installed, or is complete or near completion) is tested to verify

.

C&I Equipment used in commissioning are :

Multimeter of reputed make CRO (Cathode Ray Oscilloscope)

Tongue Tester

Cable terminating gun (Maxi Terminating tool)

Soldering station

Allen key set eca e es s ance ox

Voltage source

Ammeter source

Walkie-Talkie

2PMI Revision 01


3/17

C&I commissioning activities are broadly divided into two parts:

2) Control system commissioning

various C&I instruments ( Pressure sensor & transmitter, Temperaturesensor & transmitter, Proximity sensor , vibration Pick up, Pressure &Temperature switch ) are completed.

All field instruments are tested functionally & calibrated (where applicable)before mounting. Their respective cables are laid as per the given layoutdrawings & terminated at Junction Box.

Junction Box are weather proof generally IP65. The cables are routed tominimize possibility of damage i.e. either in conduit or pegged acrosssupport.

Mostl instrument cables are PVC insulated or flexible cables with

electromagnetic shielding. The mesh of cable is terminated at groundingstud of Junction Box.

From Junction Box cables are laid in cable trays up to Marshalling Panel.

their bolting, connectors splice plates, clamps, and bonding jumpers etc.

3PMI Revision 01


4/17

Cable tray systems are not required to be mechanically

continuous, but shall be electrically continuous. Cable tray systems that contain signal andcommunication circuits should be grounded and, in somesituations, shielded from external electrical and magnetic

.

The sensitivity of signal systems depends on a numberof complex factors. Including electronic circuitry involved,

, ,and logic, type of signal cable (untwisted pair, twisted

pair, shielded twisted pair, coaxial cable double-shielded

and cable. Some systems are quite tolerant to externalnoise. For instance, 4 to 20MA instrument signalsystems and telecommunication circuits do quite well

w t respect to no se. e most es ra e es gn s toseparate power and signal cables in separate cabletrays, or to separate wiring systems by a barrier.

4PMI Revision 01


5/17

Cable tray systems have been used extensively to support sensitiveelectronic circuitry. For many circuits shielding and separation requirements

are minimal. Pro er attention to the followin can mana e noise and EMIconcerns:

Signal cable

Grounding of signal circuits and cable shields

Cable tray grounding

Details of C&I control Panel grounding :

The purpose of grounding is:

Fire Protection

Electrical Shock Protection Electrical s stem round fault rotection

Lighting protection-building and electrical system

Electrical Noise and EMI protection

Voltage Stabilization

ec r ca ear ng a so ca e r y ear ng or ro ec ve ar ng - Instrument earthing (also called Reference Earth (RE))

- Intrinsically safe earthing

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Electrical earthing is used to protect the power system, electricalequipment, and personnel from electric shock.

How to do an electrical earthing?

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Armor of single and multi core cable going to junction box shall beterminated at cable gland. If the junction box made from metal, then

on y nee s o connec e ear s u o o e neares s eestructure. If the junction box made from non metal, the earth studbolt will be located at the metal gland plates which have directcontact with the cable gland.

Armor of single and multi core cable going inside or outsidemarshalling and system cabinet shall be terminated and connected

.be connected to a grounding dispatcher by 35 mmsq cable (usuallygreen yellow stripped). This grounding dispatcher will collect allconnection from individual bus bar and then connect it to a general

.general used, the earth bus bar is made from copper and has 1

width and height. 6PMI Revision 01


7/17

Instrument earth

Instrument earthing system shall consist of the followingeart type:

The general principle of instrument earth is all individualshields screen and overall shield screen of sin le or

multi pair cable shall be isolated from electrical earthingand terminated at different bus bar. This instrument earthusuall also called reference earth since it serve thereference point of the instrument loop (ground of internalelectric circuit inside the instrument).

terminated at earth or ground terminal block inside theinstrument enclosure.

the junction box shall be terminated to terminal block.Individual shield from digital single pair cable going inside

jump out each other then connect it to bus bar. 7PMI Revision 01


8/17

Individual shield from multi pair cable going inside the

junction box shall be also terminated to terminal blockma c w e n v ua s e rom s ng e pa r ca e.

Overall shield from multi pair analog cable going insidethe junction box shall be terminated to terminal block or

pair with the shield from single pair cable). Overall shieldfrom multi pair digital cable going inside the junction box

.

All individual and overall shields (screen) from multi pair

cable shall be terminated into respective instrument

Instrument bus bar will be connected to groundingdispatcher by 25 mmsq green-yellow stripped cable.From roundin dis atcher it will be connected to maininstrument earth loop by 70 mmsq green-yellow strippedcable.

8PMI Revision 01


9/17

Intrinsically Safe earthing

so a on an erm na on o e ca e s e s screen a edevices, junction boxes and marshalling cabinets shall be done inthe same manner as for instrument earth explained above. Howeverthe overall shield (screen) of multi pair cable for IS signals goes tomars a ng ca ne s a e erm na e n v ua y an connec e

to its IS bus bar. The individual shield (screen) of this cable will beterminated directly to a galvanic isolator and then connected to therespective IS bus bar.

The following maximum resistance limits shall be achieved after theinstrument earthing system installed. This resistance is minimized as

much as possible so the un-normal current can be safely groundedat steel structure.

Between instrument earth bus bars and grounding dispatcher notgreater than 0.5 ohm.

Between electrical equipment frame and nearest local stud earth on

. Between intrinsically safe installation and grounding dispatcher notgreater than 0.5 ohm.

9PMI Revision 01


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11/17

Calibration of C&I INSTRUMENTS:1. CALIBRATION OF BEARING VIBRATION MEASUREMENT

.2. CALIBRATION OF PR /FLOW /LEVEL TRANSMITTERS

3. CALIBRATION OF PR/DP AND TEMP SWITCHES

4. CALIBRATION OF PRESSURE SWITCHES

5. CHECKING OF LEVEL SWITCHES6. CALIBRATION OF CONTROL ROOM INDICATORS

7. CALIBRATION OF PRESSURE GAUGES

8. CALIBRATION OF PNEUMATIC CONTROL VLVS

9. Calibration of all hydraulic control valves like (HPT,LPT HP BYPASS LP BYPASS

Loop Checking and Commissioning :

Loop Checking and Commissioning of Field PT/DPT :

.Pressure transmitter will give output 4-20mA to I/P card& the pressure reading should be available at DCS endi.e at En ineerin work station. In case of malfunctioninput card or wiring needs to be checked.

11PMI Revision 01


12/17

Loop Checking and Commissioning of Field switches:

. w c as wo s a es w c can e s mu a e rom eend & status can be checked in Engineering work station.

Proximity switch status can be checked by moving the target nearto switch & its status may be checked in EWS.

Loop Checking and Commissioning of Temperature transmitters:

empera ure a ra or may e use o s mu a e e e con onthe temperature value may be checked in EWS.

12PMI Revision 01


13/17

Loop Checking and Commissioning of Drives:

During commissioning, no of drives cannot be,

discharge line may not be installed. In this case firstisolation of Lub oil p/p must be ensured so it wont

.made in module by shorting a certain no. of terminals

the Drive feedback on , feedback off, feedback not on,,EWS. For Drive on command , From EWS the bit canbe made high & at module 24V Dc may be checked

.

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ALARMS CHECKING

arm c ec ng s a e ous process as ere are

no. of alarms associated with an equipment.

,

alerts the plant operator in advance of anymalfunction in rocess side. Alarms initiated

from field end can be simulated by shorting or

opening switch & cross verified in SOE , LVSalarm panel (if provision for that alarm is given ).

Some of the alarm are system generated so in

design.

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PROTECTION & INTERLOCK CHECKING:

Protection is vital part of C&I commissioning as theequipment must trip in order to safeguard any damage.Since Equipment cannot be tripped every time duringprotection check so proper isolation is done like its mainpower supply must be switched off & its tripping signalcan be checked at Marshallin Panel or in EWS once theprotection is initiated whether from field or from DCSside.

as FD Fan is switched on its discharge damper shouldopen in auto. To simulate the above given condition FD

Marshalling panel or EWS & the damper should not openin field therefore it is isolated & the damper open

EWS and at Electrical module.16PMI Revision 01


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C&I Commissioning 001

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