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Multiple services & Neutral bonding #5232
11/09/01 07:10 PM
11/09/01 07:10 PM
P
pauluk  Offline OP
Member
Joined: Aug 2001
Posts: 7,520
Norfolk, England
A couple of topics here got me to thinking some more about multiple services to a building.

Suppose you have a commercial building fed with 277/480V Wye. O.K, so perhaps in most cases there would be a customer-owned xfmr to get local 120/208 service, but what if the PoCo provides a separate 120/208V Wye (or a 1-ph 3-w 120/240V supply).

If the NEC requires neutral-ground bonding at each main panel, how does the PoCo feel about having the neutrals of two different services effectively connected together in this way?

Work Gear for Electricians and the Trades
Re: Multiple services & Neutral bonding #5233
11/09/01 09:01 PM
11/09/01 09:01 PM
E
ElectricAL  Offline
Member
Joined: Oct 2001
Posts: 597
Minneapolis, MN USA
In my experience, the power company enforces the grounding of the neutral at the building as part of their pre-energization tests, even when there is no other AHJ. In the un-inspected areas I have experienced, the PoCo lineman will make sure the neutral is bonded to ground before he runs the service lateral. . .anything else may well be ignored, but not that. I take that as evidence that the PoCo is all for the neutral ground bond even when it cross neutrals different systems.

Al


Al Hildenbrand
Re: Multiple services & Neutral bonding #5234
11/09/01 10:18 PM
11/09/01 10:18 PM
S
sparky  Offline
Member
Joined: Oct 2000
Posts: 5,360
There really cannot be any true N isolation with the N&G practice used here, be it under one roof, or having a common municipal bond.

Re: Multiple services & Neutral bonding #5235
11/10/01 07:20 AM
11/10/01 07:20 AM
P
pauluk  Offline OP
Member
Joined: Aug 2001
Posts: 7,520
Norfolk, England
Yeah, that's pretty much what I was thinking from the recent posts on this.

I can see more of this discussion arising in the U.K. with the increasing use of PME (i.e. bonded N-G).

Re: Multiple services & Neutral bonding #5236
11/10/01 07:50 AM
11/10/01 07:50 AM
S
sparky  Offline
Member
Joined: Oct 2000
Posts: 5,360
There has been, ROP's as i understand, as to a N-G separation back to the serving X-former. The NEC has dictated 'codes' for many other trades, but that seems to stop at the utilities, who seem impenetrable.

Re: Multiple services & Neutral bonding #5237
11/10/01 01:05 PM
11/10/01 01:05 PM
P
pauluk  Offline OP
Member
Joined: Aug 2001
Posts: 7,520
Norfolk, England
Something like the U.K. system in my diagram #1, you mean? I have to confess that I like that system a lot, although I wouldn't be adverse to installing a ground rod at each house as well, just to be certain.

What's ROP by the way?

Re: Multiple services & Neutral bonding #5238
11/10/01 05:52 PM
11/10/01 05:52 PM
electure  Offline

Member
Joined: Dec 2000
Posts: 4,274
Fullerton, CA USA
Way off the subject, but we have a "Regional Occupational Program"(ROP) in the high schools here, which teaches mainly agricultural occupations.
Here in North Orange County, it is abbreviated as NO CROP [Linked Image]

Re: Multiple services & Neutral bonding #5239
11/11/01 09:20 AM
11/11/01 09:20 AM
S
sparky  Offline
Member
Joined: Oct 2000
Posts: 5,360
Scott, soundslike a federal program [Linked Image]

Paul; http://www.nfpa.org/Codes/National_Electrical_CodeR__NEC/Proposals/necpdf/A250.PDF
ROP= Report on Proposal, anyone can write and submit one, but it usually needs to be of indisputable quailty to amount to an NEC change.

there are ROC's = Report on comments, where there are some points of views that are , at least in my opinion, real rippers. One individual's letter on the recent change of 'fixture' to 'lumiaire' eluded to plumbers mistakenly mounting toilets on kitchen cielings , absolute 5-star ripper! [Linked Image]

Re: Multiple services & Neutral bonding #5240
11/12/01 04:39 PM
11/12/01 04:39 PM
Scott35  Offline

Broom Pusher and
Member
Joined: Oct 2000
Posts: 2,708
Anaheim, CA. USA
Scott [electure],

Haven't heard about NOCROP for years!!! I learned Diesel Mechanics in 1982-3 at Loara High School in a NOCROP program.
Give me a call sometime [Linked Image]

As to this thread;

I have seen a few PoCo supplied systems / services as described. Seems to me that the whole thing would be as any other type of "Dual Services" or even SDS [Separately Derived System] would be - as far as the Grounding / Grounding Electrode System is concerned.

Just my thoughts.

Scott SET.


Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!

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