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 13
HotLine1 9
Texas_Ranger 8
sparkyinak 7
Trumpy 6
Who's Online
0 registered (), 284 Guests and 4 Spiders online.
Key: Admin, Global Mod, Mod
Page 1 of 2 1 2 >
Topic Options
Rate This Topic
#85400 - 06/30/03 03:48 AM 250.32 Q's
sparky Offline
Member

Registered: 10/18/00
Posts: 5545
Building A has a service w/GEC's, and a feeder is run from building B to building A (re; subpanel)

~does said subpanel need a GEC if the building already has one?

~if so, should GEC's from different x-formers be married together?

 Quote:
250.32 Two or More Buildings or Structures Supplied from a Common Service.

(A) Grounding Electrode. Where two or more buildings or structures are supplied from a common ac service by a feeder(s) or branch circuit(s), the grounding electrode(s) required in Part III of this article at each building or structure shall be connected in the manner specified in 250.32(B) or (C). Where there are no existing grounding electrodes, the grounding electrode(s) required in Part III of this article shall be installed.


[This message has been edited by sparky (edited 07-01-2003).]

Top
2014 / 2011 NEC & Related Books and Study Guides
#85401 - 06/30/03 06:30 PM Re: 250.32 Q's
txsparky Offline
Member

Registered: 05/25/01
Posts: 578
Loc: Magnolia,.Texas U.S.A.
 Quote:
~ should GEC's from different x-formers be married together?

It is done all of the time. Consider a multi-story building where the building steel is used as the grounding electrode for all of the x-fmers in the building.
_________________________
Donnie

Top
#85402 - 07/01/03 02:54 AM Re: 250.32 Q's
PCBelarge Offline
Member

Registered: 06/08/03
Posts: 657
Loc: Dobbs Ferry, NY, USA
Sparky

Just a 'dumb question', if there is already service in the building why are you running a subpanel to it from another building? Just curious.

Pierre
_________________________
Pierre Belarge

Top
#85403 - 07/01/03 03:17 AM Re: 250.32 Q's
sparky Offline
Member

Registered: 10/18/00
Posts: 5545
Pierre, economics....
the original service (5 meters) is a mess, and at the other end of a long building.

This feeder was available by way of an unsued meter/main nearby

Top
#85404 - 07/01/03 09:17 AM Re: 250.32 Q's
resqcapt19 Offline
Member

Registered: 11/10/00
Posts: 2209
Loc: IL
sparky,
Are you in compliance with 230.2 and 225.30?
Don
_________________________
Don(resqcapt19)

Top
#85405 - 07/01/03 02:18 PM Re: 250.32 Q's
sparky Offline
Member

Registered: 10/18/00
Posts: 5545
Don,
it is a feeder, so 230.2 (i believe) would not apply, 225.30 OTOH...
 Quote:
225.30 Number of Supplies.
Where more than one building or other structure is on the same property and under single management, each additional building or other structure served that is on the load side of the service disconnecting means shall be supplied by one feeder or branch circuit unless permitted in 225.30(A) through (E). For the purpose of this section, a multiwire branch circuit shall be considered a single circuit.


would seem to consider outbuildings downstream of the main service, limiting the # of feeders or branch circuits per stipulations.

there are two building on the same property here, via the same owner, each has a service drop.

Building A is a large long 5 unit apt house w/barn.

Said barn is being supplied from building B's exclusive service, via a feeder to A


what am i missing?

~S

Top
#85406 - 07/01/03 07:33 PM Re: 250.32 Q's
resqcapt19 Offline
Member

Registered: 11/10/00
Posts: 2209
Loc: IL
In my opinion, you can't feed a building that already has a service with a feeder from a second building. You need to check with the AHJ before making this installation. The code intent is to have a single source of supply for each building.
Don
_________________________
Don(resqcapt19)

Top
#85407 - 07/02/03 03:33 AM Re: 250.32 Q's
sparky Offline
Member

Registered: 10/18/00
Posts: 5545
hmmm, well if it is pertinent,i believe the barn that is fed here has been ordered firewalled off from the rest of the building.

Top
#85408 - 07/02/03 04:41 AM Re: 250.32 Q's
Gwz Offline
Member

Registered: 04/29/02
Posts: 199
I agree with Don about a building having only one supply source.

BUT, what would happen if a 1 to 1 isolation transformer was installed in the feeder of a second source to a building. Would this be considered separately derived?


Article

100 Service
100 Feeder
100 Separately Derived System
100 Premise Wiring (System)
230 cover utility supplied
250 covers GROUNDING.

and probably other Articles.

Top
#85409 - 07/17/03 04:07 PM Re: 250.32 Q's
tdhorne Offline
Member

Registered: 03/22/01
Posts: 344
Loc: Maryland, USA
Take pitty on us poor jakes (firefighters) and at least clearly mark both disconnecting means to indicate the two supplies and their locations.
--
Tom
_________________________
Tom Horne

"This alternating current stuff is just a fad. It is much too dangerous for general use" Thomas Alva Edison

Top
Page 1 of 2 1 2 >



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