Generator Serving 2 Buildings

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pk04607

Member
Location
Maine
I have an industrial customer that has a back up generator serving a panel in one building and wants me to pick up a load (a vacuum pump)in another building using the same panel. Is this legal? Please give code references. Thanks,Pat.
 
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dlhoule

Senior Member
Location
Michigan
This is out of my area of expertise and no code references. It would seem to me that with proper labeling you could feed that pump out of that panel. How is the pump currently being fed?
 

pk04607

Member
Location
Maine
Thanks for the reply Larry, Not my area of expertise either, hence the question. The pump is going to be a new installation. Pat.
 

pk04607

Member
Location
Maine
Hi Charles, Thanks for your reply. I read 225.30(A)(4) (2005 NEC). and might be missing the mark but that that looks like a supply for a battery charger or ? Again this is not my area of expertise. Hopefully someone will come along and school me up. Pat.
 

russ

Senior Member
Location
Burbank IL
If this is a Optinal Standby System (Article 702), and meets all the requirements in 702, I can't see a problem.
 

pk04607

Member
Location
Maine
Hi Russ, Thanks for your reply, I guess my first thought is when you enter power into another building from any supply other than the main service it posses a threat to fire fighters when they dump the main to the building and believe there's no power. That's why I'm concerned about this being legal and of course the liability of doing it. Pat.
 

Nick

Senior Member
You will have to terminate the generator feeder in a service rated disconnect at the building and bond the generator feeders equipment ground to the buildings ground system. There is also some labeling requirements but I am going off memory right now.
 

pk04607

Member
Location
Maine
Hi Nick, Thanks for your reply,Let me see I've got this right. You're saying I can run the vacuum pump in building 2 off the generator fed panel in building 1 if I first terminate the branch circuit in a service rated disconnect in building 2 and bond the equipment ground to the buildings ground system. I then need labeling in both buildings. If you or anyone knows code reference for this installation (including labeling requirements) I'ld appreciate it. I'm sure I'll be dealing with an AHJ on it. Thanks, Pat.
 

dlhoule

Senior Member
Location
Michigan
pk04607 said:
Hi Nick, Thanks for your reply,Let me see I've got this right. You're saying I can run the vacuum pump in building 2 off the generator fed panel in building 1 if I first terminate the branch circuit in a service rated disconnect in building 2 and bond the equipment ground to the buildings ground system. I then need labeling in both buildings. If you or anyone knows code reference for this installation (including labeling requirements) I'ld appreciate it. I'm sure I'll be dealing with an AHJ on it. Thanks, Pat.

Why not talk with the AHJ about it before you go any farther? If he doesn't have the answer, he should know how to get it.
 

iwire

Moderator
Staff member
Location
Massachusetts
I am really missing the problem.

On campus type facilities it is quite normal to have a centrally located generator supplying multiple buildings.
 

George Stolz

Moderator
Staff member
Location
Windsor, CO NEC: 2017
Occupation
Service Manager
Pat, I'm assuming the main cause of the question you have is that the second building is already served by a service or outside feeder.

If you identify the sources of supply as required in 225.37, and group them as required in 225.33, and use a disconnect rated for use as service equipment (225.36), you should be fine.

Depending on rating of the circuit in question, a simple A/C disconnect could suffice. Square D makes one rated for service use, I installed one on an A/C last week. :)
 

pk04607

Member
Location
Maine
Hi Bob, Thanks for your reply, I thought it might be a problem to have the generator feeding the panel in building 1 and then running a branch circuit out of that panel to building 2. Pat.
 

pk04607

Member
Location
Maine
Hi George, Thanks for your reply, I also thought it might be a problem to have the generator feeding the panel in building 1 and then running a branch circuit out of that panel to building 2. Pat.
 
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