Presented  By:  Bob  Trivedi,  P.E.  

Elara  Engineering  

Seminar  Highlights    

  Brief  introduc5on  of  basic  electrical  engineering  ….only  the  important  stuff.  

  The  design  issues  that  mechanical  engineers  need  to  consider.  

  Keys  to  achieving  a  successful  project  in  a  5me  sensi5ve  environment.  

  Coordina5on  between  the  mechanical  and  electrical  disciplines.  

Formulas,  Formulas,  more  Formulas    Symbolic:      E  =VOLTS  ~or~  (V  =  VOLTS)  ,              P  =WATTS  ~or~  (W  =  WATTS)      R  =  OHMS  ~or~  (R  =  RESISTANCE),              I  =AMPERES  ~or~  (A  =  AMPERES)      HP  =  HORSEPOWER,            PF  =  POWER  FACTOR      kW  =  KILOWATTS,              kWh  =  KILOWATT  HOUR      VA  =  VOLT-­‐AMPERES,                kVA  =  KILOVOLT-­‐AMPERES      EFF  =  EFFICIENCY    DIRECT  CURRENT  AMPS=  WATTS÷VOLTS,                I  =  P  ÷  E,                A  =  W  ÷  V      WATTS=  VOLTS  x  AMPS,            P  =  E  x  I,            W  =  V  x  A      VOLTS=  WATTS  ÷  AMPS,            E  =  P  ÷  I,            V  =  W  ÷  A      HORSEPOWER=  (V  x  A  x  EFF)÷746      EFFICIENCY=  (746  x  HP)÷(V  x  A)    

  AC  SINGLE  PHASE  ~  1ø     AMPS=  WATTS÷(VOLTS  x  PF),          I=P÷(E  x  PF),            A=W÷(V  x  PF)      WATTS=  VOLTS  x  AMPS  x  PF,            P=E  x  I  x  PF,              W=V  x  A  x  PF      VOLTS=  WATTS÷AMPS,          E=P÷I,            V=W÷A      VOLT-­‐AMPS=  VOLTS  x  AMPS,            VA=E  x  I,          VA=V  x  A      HORSEPOWER=  (V  x  A  x  EFF  x  PF)÷746      POWER  FACTOR=  INPUT  WATTS÷(V  x  A),          EFFICIENCY=  (746  x  HP)÷(V  x  A  x  PF)    

  AC  THREE  PHASE  ~  3ø      AMPS=  WATTS÷(1.732  x  VOLTS  x  PF),            I  =  P÷(1.732  x  E  x  PF)    WATTS=  1.732  x  VOLTS  x  AMPS  x  PF,              P  =  1.732  x  E  x  I  x  PF,          VOLTS=  WATTS÷AMPS  E=P÷I      VOLT-­‐AMPS=  1.732  x  VOLTS  x  AMPS,        VA=1.732  x  E  x  I      HORSEPOWER=  (1.732  x  V  x  A  x  EFF  x  PF)÷746      POWERFACTOR=  INPUT  WATTS÷(1.732  x  V  x  A)      EFFICIENCY=  (746  x  HP)÷(1.732  x  V  x  A  x  PF)  

  The  source  of  power  for  most  buildings  comes  from  the  energy  u5lity.  Power  is  generated  at  the  u5lity  and  then  transmiced  to  the  end  users  through  an  extensive  distribu5on  network.  

  The  power  that  we  typically  u5lize  is  either    120V,  208V  or  480V.      Other  voltages  are  delivered  depending  on  the  type  of  facility.    

  It  is  important  to  know  what  voltage  is  available  before  we  begin  selec5ng  equipment.  

WHERE  DOES  THE  POWER  COME  FROM?.........  

MAIN  SWITCHGEAR  

THIS  IS  WHERE  IT  ALL  STARTS……..  

PANEL  LOCATIONS  ARE  IMPORTANT.  

KEEP  ALL  MAJOR  EQUIPMENT  NEAR  THE  SOURCE.  

MAINTAIN  PROPER  ACCESS.  

SAFETY  IS  ALWAYS  THE  FIRST  PRIORITY…..WATCH  WHERE  YOU  PUT  YOUR  

HAND!!!  

IMAGE  OF  A  LIVE  FRONT  PANEL  

IMAGE  OF  A  CONBINATION  STARTER  

A  MOTOR  STARTER  IS  AN  IMPORTANT  COMPONENT  BECAUSE  IT  ALLOWS  US  TO  REMOTELY  POWER  A  MOTOR  (PUMP,  FAN,  ETC.)  WHEN  NEEDED,  AS  WELL  AS  POWER  IT  DOWN.  

IT  PROTECTS  ITSELF  FROM  ELECTRICAL  OVERLOAD  AND  SAVES  SENSITIVE  MACHINERY  COMPONENTS  FROM  DAMAGE.  

MOTOR  STARTERS:  

DISCONNECT  SWITCHES:  

DISCONNECT  SWITCHES  COME  IN  A  VARIETY  OF  SIZES  AND  VARY  DEPENDING  ON  THE  APPLICATION:  

• INDOOR  • OUTDOOR  • FUSED  AND  NON-­‐FUSED  • AUX.  CONTACTS  

Variable  Frequency  Drives    

• VFDs  ARE  USED  EXTENSIVELY  TO    CONTROL  PUMPS  AND  AIR  HANDLING  SYSTEMS  

• WE  NEED  TO  CONSIDER  OPTIONS:  

 INTEGRAL  FUSED  DISCONNECT   CONTROLS  INTERFACE   FULL  ELECTRICAL  BYPASS    

DESIGN  CONSIDERATIONS  

Some  important  design  related  issues  that  we  need  to  consider  :  

 What  is  the  service  size  and  voltage?   What  is  the  new  load  (equipment  power)?    How  far  are  we  from  the  nearest  power  source?    Do  we  need  EM  power?    Do  I  need  any  special  power  connec5ons?   Who  is  responsible  for  misc.  wiring,  controls,  etc.?    Starter,  Disconnect,  VFD….?????.....Who  provides?  

                       

Interes5ng  Design  Facts      Ligh5ng  load  is  typically  1  wac  per  square  foot  of  building  area.  

  Receptacle  load  is  typically  1  to  2  wacs  per  square  foot  of  building  area.  

 HVAC  loads  are  typically  5  or  more  wacs  per  square  foot  of  building  area!!!!  

WHAT  CAN  YOU  DO  TO  HELP  THE  ELECTRICAL  ENGINEER  AND  SPEED  UP  THE  DESIGN  PROCESS??  

THE  ELECTRICAL  ENGINEER  IS  WORKING    AGAINST  THE  SAME  DEADLINES  YOU  ARE.  HERE  ARE  A  FEW  IDEAS  TO  HELP  THEM  COMPLETE  THEIR  DESIGN  WITHOUT  THEM  HAVING  TO  FALL  BEHIND.  

1)  Layout  the  loca5ons  of  the  major  HVAC  equipment.  2)  Provide  load  data  (even  good  es5mates)  ASAP!  3)  Coordinate  who  provides  disconnects,  VFDs  etc.  on  the  front  

end.  4)  Discuss  any  misc.  components,  sensors,  wiring  that  needs  to  

be  addressed  by  the  contractors.  5)  Don’t  forget  that  some  equipment  needs  more  than  one  

power  feed  (lights,  misc  heaters,  control  circuits,  etc.).  It  is  not  always  a  single  point  connec5on.  

6)  Review  safety  devices,  controls  circuits,  equipment  opera5on.  

7)  Provide  final  equipment  cut  sheets  as  soon  as  the  they  are  available  with  wiring  diagrams…..always  the  wiring  diagrams!  

8)  Listen  to  the  Electrical  Engineers  concerns…….we  can  avoid  major  issues  this  way.  

How  do  you  improve  the  process?  

 Project  task  list  

 Coordina5on  Schedule  

 Communica5on  

Project  Task  List  :  

• Details  all  required  tasks  that  need  to  be  completed  by  each  discipline  

• Helps  to  track  design  progress  

• Indicates  comple5on  percentages  

• Helps  to  focus  acen5on  on  major  design  items  that  affect  other  disciplines  

Coordina5on  Schedule:  

• Details  responsibility  between  contractors  

• Details  what  items  are  to  be  furnished  under  each  contractors  scope  

• Helps  to  focus  acen5on  on  equipment  and  accessories  

Summary    •   Iden5fy  available  voltages.  

•   Iden5fy  new  electrical  loads.  

•   Iden5fy  any  special  considera5ons  (VFDs,  EM,  etc.)  

• Involve  all  team  members  as  early  in  the  design  process  as  possible  

•   Provide  preliminary  data  to  begin  the  electrical  design  process  as  early  as  possible,  then  provide  final  data  as  soon  as  it  is  available  

•   Coordinate  contractor  and  engineer  responsibili5es  (i.e.  who  provides  what)  

•   Communicate  and  adopt  a  project  task  list  

QUESTIONS?  

btrivedi

Snapshot

Project Task List

MECHANICAL % Complete Notes

Load Calculations

Input initial load info into Trace

Run Trace output on a space by space basis

Run energy calc in Trace

Run Energy Model

System Selections

Determine best system type to use

Geothermal

Hybrid geo/heat pump

Conventional

Equipment

Selection of AHU and Return Fan

Determine the quantity and location of AHU's, MAU's

Complete layout of supply and return ductwork (inc. roof)

Show major duct runs only

VAV boxes should be noted but not shown

Perform static pressure calculations

Confirm loads to determine fan cfm, hp, CC, HC

Toilet Exhaust Fan

Determine exhasut requirement for toilets/ Janitors closet

Select fans, cfm, hp

Determine location for exhasut fans: roof, ceilings

VAV Boxes

Provide sizing criteria based on cfm for contractor use

Diffusers, Registers, Grilles

Provide a general list of diffuser types and models per sapce

Pumps and Accessories

Select pumps for AHU and reheat coil requirements

Chilled water pumps

Pre-heat Pump

Ductwork

Finalize CFM requirements for all spaces/zones

Layout main supply and return ducts(avoid existing utilities)

Layout location of VAV boxes (accessibility critical)

Layout supply distribution from main to VAVs

Layout supply distribution from VAVs to diffusers

Layout return duct from plenum to RF

Verify pressure drop calcs and make adj. to AHU/RF as req'd.

Finalize diffuser selections and locations

Size, type, quantity and color

Coordinate locations with RCP, lights, arch ceiling effects

Layout exhaust ductwork for toilets and Janitor's closet

Verify pressure drop calc and adj fan static as req'd.

Prepare airflow diagram to represent system

Review fire damper requirements and locations

Return duct insulation requirements ?? - Review with Abbott

Piping

Verify existing pre-heat and re-heat capacities

?? Existing capacity to serve new AHU requirements

Additional HX capacity available if pressure is increased (60# to 150#)

Verify HX loads and capacities

Determine tie-in points for utilities

Chilled water loaction in lower mech room

Pre-heat location in lower level mech room

Re-heat location in lower level mech room

Humidifier Steam piping (15#) located in upper mech room

Determine pumping requirements

Chilled water needs pump

Pre-heat ?? (50% ethyl glycol - capacity and additional glycol)

Re-heat ?? - serves serves VAVs

Select pumps for above utilities as req'd.

Capacity

Head calculation

Type (base or in-line)

Location

Accessories (SD, TDV, pads, gauges, thermo, DP)

Distribution

Routing of chw, pre-heat and re-heat to AHU (and sizing)

Routing and sizing of re-heat to VAV boxes

Stm./cond to AHU

Determine required shut downs for utilities

PID - piping and instrumentation diagram for piping systems

Chilled water

Pre-heat

Re-heat

Steam and condensate

CV's, gauges, thermo, sizes, gpm, control devices, flow arrows

Determine conflicts between existing piping and new duct routing

Demolition, rearrangement and rerouting of existing piping

Plan drawings to have PS #s, pipie system tags, sizing, flow arrows

Details

VAV box connection (duct and piping)

Ductwork connection

Coil connection at AHU

Humidifier connection

Traps

Condensate

Steam condensate

Return Fan on roof

Penetrations

Exterior ductwork

Curbs

Toilet Exhasut Fan

Penetrations

Curbs

Exterior Duct Support

Pipe and duct hanging/ support details

Base mounted (in-line) pumps

Diffuser connection

2x2

Linear slot

Schedules

AHU

Return Fan

Toilet Exhaust

VAV Boxes

Reheat coils (VAV)

Control Valves

AHU (Masoneilan)

VAV (Siemens)

Humidifier (Masoneilan)

Humidifier

Diffusers, registers, grilles

Pumps

Steam traps

Fire Dampers

STRUCTURAL

AHU Pad or rails

Return fan roof support (curbs)

Return fan roof duct penetrations

Hot water heater wall supports

Toilet exhaust fan curbs

PLUMBING

Fixture cuts from Mark Tropinski

Faucet cuts from Mark Tropinski

Underground plumbing piping

Above ground piping distribution

Cold water

Hot water

Hot water return

Vent

Select electric water heater

Finalize location for HWH with Mark Tropinski

Layout piping

Isometric

Sizing of piping

Connection to existing sanitary

Connection to existing FW

2.5" valve at main RPZ

FW line size

Demolition of existing toilets

Plumbing details

Plumbing Schedules

Water fountains

Cuts from Mark Tropinski

CONTROLS

T-stat locations for VAV boxes

Open area stats are critical

Airflow measuring stations for AHU and RF

Fan mounted ??

ELECTRICAL

Determine power requirements

Workstations

Offices

Conference rooms

Fill line and workstations

Electric water heater

Water fountains

IT room (panels, filters, dedicated gnd.?)

Lighting loads

Review existing panels locations and determine main distribution

Panel location and quantities

Transformers

Lighting layout

Finalize fixtures

Check photometrics

Finalize fixture layout in RCP

277/480v panel requirements and placement

120/208v panel requirements and placement

Lighting controls

Square D control panel

Occupancy sensors

EM lights

Exit signs

Underfloor duct distribution

Layout for demo package

Transformer selcetion and sizing

Electric room layout

Electric room and IT room cooling requirements

Fire Panel

Smoke detectors

AHU

Space

IT room

Electric room

FIRE PROTECTION

Review existing piping and head layout

Determine space FP requirements

Hazzard

Head type

Head layout (coordination with RCP)

Piping requirements

Calculations

Zone Valves

Fire Panel interface

Reconfiguration of existing piping