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

   
Topic Options
Rate This Topic
#5232 - 11/09/01 03:10 PM Multiple services & Neutral bonding
pauluk Offline
Member
Registered: 08/11/01
Posts: 7693
Loc: 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?
Top
Work Gear for Electricians and the Trades
#5233 - 11/09/01 05:01 PM Re: Multiple services & Neutral bonding
ElectricAL Offline
Member
Registered: 10/10/01
Posts: 615
Loc: 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
Top
#5234 - 11/09/01 06:18 PM Re: Multiple services & Neutral bonding
sparky Offline
Member
Registered: 10/18/00
Posts: 5545
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.
Top
#5235 - 11/10/01 03:20 AM Re: Multiple services & Neutral bonding
pauluk Offline
Member
Registered: 08/11/01
Posts: 7693
Loc: 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).
Top
#5236 - 11/10/01 03:50 AM Re: Multiple services & Neutral bonding
sparky Offline
Member
Registered: 10/18/00
Posts: 5545
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.
Top
#5237 - 11/10/01 09:05 AM Re: Multiple services & Neutral bonding
pauluk Offline
Member
Registered: 08/11/01
Posts: 7693
Loc: 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?
Top
#5238 - 11/10/01 01:52 PM Re: Multiple services & Neutral bonding
electure Offline


Member
Registered: 12/24/00
Posts: 4229
Loc: 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
Top
#5239 - 11/11/01 05:20 AM Re: Multiple services & Neutral bonding
sparky Offline
Member
Registered: 10/18/00
Posts: 5545
Scott, soundslike a federal program

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

Broom Pusher and
Member
Registered: 10/19/00
Posts: 2724
Loc: 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

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!
Top

Featured:

2017 NEC and Related
2017 NEC
Now Available!

Shout Box

Recent Posts
Looking for older post
by sparkyinak
Today at 12:27 AM
License exam
by TRUE POWER
Yesterday at 11:33 PM
Members: Non-Members: Did you know?
by Admin
Yesterday at 02:34 PM
Safety at heights?
by HotLine1
01/21/17 08:51 PM
International Wire Colour Codes
by Texas_Ranger
01/21/17 03:29 PM

Who's Online
0 registered (), 90 Guests and 9 Spiders online.
Key: Admin, Global Mod, Mod
New in the Gallery:
Desk-mounted "power-board"
Top Posters
gfretwell 9066
Trumpy 8560
pauluk 7693
HotLine1 6833
sparky 5545
Member Spotlight
Member Since: 02/21/04
Posts: 1248

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