The Electrical Contractor Network

ECN Electrical Forum
Discussion Forums for Electricians, Inspectors and Related Professionals

Books, Tools and Test Equipment for Electrical and Construction Trades

Register Now!

Register Now!

We want your input!

Featured:
   

2017 NEC and Related
2017 NEC
Now Available!

   
Recent Posts
Sprinklered equipment 26-008
by bigpapa
12/02/16 04:24 PM
On Delay Relay with Auto Reset
by Potseal
12/01/16 09:59 AM
Wow, that was close!
by jraef
11/28/16 07:06 PM
Earthquake in New Zeeland
by RODALCO
11/27/16 11:25 PM
Calling all Non-US members!! (Non-US only)
by Tjia1981
11/27/16 06:33 AM
New in the Gallery:
12.5A through 0.75mm˛ flex (just out of curiosity)
Shout Box

Top Posters (30 Days)
gfretwell 14
HotLine1 10
Trumpy 8
Texas_Ranger 8
sparkyinak 7
Who's Online
0 registered (), 198 Guests and 5 Spiders online.
Key: Admin, Global Mod, Mod
Topic Options
Rate This Topic
#190025 - 11/03/09 01:05 PM Fire Pumps 695
Yoopersup Offline
Member

Registered: 03/04/03
Posts: 826
Loc: Michigan
Em. Generator Breaker off that feeding service rated Firepump controller/Transfer Switch..
Service from Transformer feeding service rated fire pump controller/transfer switch (same).
From Generator Since breakers on Gen. Set its a Feeder.
From Transformer to to Service rated control/Transfer switch its Service conductors.
Generator side its 3 hots & Ground.
Transformer side its 3 hots & Neutal.(250.24C)
Neural & Ground terminate together at this point ????

Any one else run into this???
Yoopersup

Top
2014 / 2011 NEC & Related Books and Study Guides
#190054 - 11/04/09 11:04 AM Re: Fire Pumps 695 [Re: Yoopersup]
SteveFehr Offline
Member

Registered: 03/19/05
Posts: 1192
Loc: Chesapeake, VA
Originally Posted By: Yoopersup
Em. Generator Breaker off that feeding service rated Firepump controller/Transfer Switch..
Service from Transformer feeding service rated fire pump controller/transfer switch (same).
From Generator Since breakers on Gen. Set its a Feeder.
From Transformer to to Service rated control/Transfer switch its Service conductors.
Generator side its 3 hots & Ground.
Transformer side its 3 hots & Neutal.(250.24C)
Neural & Ground terminate together at this point ????

Any one else run into this???
Yoopersup
If it's a delta generator, I hope it's a delta pump. If it's a delta pump, you don't need a neutral. 250.24(C) doesn't apply to delta panels, as the AC system is not grounded at any point.

Easy answer: don't run the neutral.

Top
#190058 - 11/04/09 12:39 PM Re: Fire Pumps 695 [Re: SteveFehr]
Yoopersup Offline
Member

Registered: 03/04/03
Posts: 826
Loc: Michigan
480/277 Volt System at both Generator & Service Thus Neutral required per 250.24c to ist disconnect switch per code.Since Feeder Neutral is not required only equipment gr. But Service requires Neutral.
Yoopersup

Top



ECN Electrical Forums - sponsored by Electrical Contractor Network - Electrical and Code Related Discussion for Electrical Contractors, Electricians, Inspectors, Instructors, Engineers and other related Professionals