ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Shout Box
Recent Posts
Motion detectors and dimmers
by gfretwell. 09/20/18 04:02 PM
Extension cords
by annemarie1. 09/20/18 08:54 AM
Inspection camera help
by Bill Addiss. 09/19/18 10:50 PM
220/230/240V 60Hz Systems
by gfretwell. 09/16/18 12:37 PM
Acronis Backup 2017
by gfretwell. 09/16/18 12:46 AM
New in the Gallery:
Plug terminals
Housebilding DIY wiring
Who's Online Now
0 registered members (), 24 guests, and 25 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
emergency generator 2 bldgs #80654
05/04/02 10:26 PM
05/04/02 10:26 PM
C
Cindy  Offline OP
Member
Joined: Jun 2001
Posts: 196
PDX, OR, US
i'm really weak on generators and emergency circuits..... ok, i'm weak on everything [Linked Image] anyway, plans are showing an emergency generator serving two buildings [one existing with the e-gen. and one planned] on the same property, but it doesnt show a disconnect entering the new bldg or a transfer switch at the generator.. all it shows is a single emergency power circuit coming from the existing buildings generator.

is a transfer switch at the generator location the correct way to do this? 700.6

is it allowed to use a relay at the second building to signal the generator that the e-circuits are needed?

and i assume i would need to put phenolic labels at both buildings even if its only e-power? 225.37 for svc. 700.8 for gen.

225.31 says it needs a disconnect regardless of their being emergency circuits or normal? and to be s.u.s.e. 225.36

anything else?

2017 / 2014 NEC & Related Books and Study Guides
Re: emergency generator 2 bldgs #80655
05/07/02 07:01 AM
05/07/02 07:01 AM
G
George Corron  Offline
Member
Joined: May 2001
Posts: 717
Lorton, Va USA
Cindy,
Sorry, your question deserved an answer before this. You answered most of them though, and did raise a few more.

We assume here that the buildings are on the same circuit from the utility, if not, some answers change. IF they are, then only one transfer switch would be necessary, since if the utility fails, it would start.

If you are using this genset to replace emergency batteries (unit equipment) then yes, you should put a relay in the second building, and could put a second transfer switch in that would transfer ONLY that building. I would view that as optional, since generally the idea behind emergency equipment is to guard against utility failure, and that is covered with the one transfer switch. Realize that unless your doing this in No. Va. , I can't speak for your local AHJ.

Yup, I would say 700-6, 701-7, 702-6 all state that labeling at the service is required.

The relay at the second building (I assume you mean a start relay here) would signal the genset to take the em load of BOTH buildings, but yeah, there's nothing illegal about this, I just think it unneccessary. Again we are concerned about Utility failure, and we should have that covered with the K relays in the xfr switch.

445-10 says the disconnect may or may not be necessary (probably not) but I don't know exactly what type of equipment you have here. The transfer sw. is a disconnect, and you can (probably) shut the genset down.

Clear as mud????????? Good luck.

Re: emergency generator 2 bldgs #80656
05/07/02 11:37 PM
05/07/02 11:37 PM
C
Cindy  Offline OP
Member
Joined: Jun 2001
Posts: 196
PDX, OR, US
both buildings are on the same transformer with a transfer switch at the existing building generator, so i guess thats enough as long as its ok to connect both buildings e-circuits into the same transfer switch.
about 445-10, not too sure how readily it could be shut down, doesnt seem like too good of an idea to have to run through a parking lot and enter the generator area to shut it down. thanks


Featured:

2017 Master Electrician Exam Preparation Combos
2017 NEC Electrician
Exam Prep Combos:
Master / Journeyman

 

Member Spotlight
Potseal
Potseal
Saskatchewan
Posts: 264
Joined: February 2013
Show All Member Profiles 
Top Posters(30 Days)
Admin 13
Trumpy 11
Popular Topics(Views)
249,359 Are you busy
187,292 Re: Forum
176,641 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.6.1
(Release build 20180101)
Page Time: 0.015s Queries: 14 (0.004s) Memory: 0.9522 MB (Peak: 1.0758 MB) Zlib enabled. Server Time: 2018-09-22 03:20:45 UTC