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Joined: Aug 2003
Posts: 4
R
Junior Member
Hi, Does Detroit Edison still make the homeowner or the Electricain hook-up the service drop? Detroit edison stopped doing service hook-up's in the late 80's.


Thanks, Rob.

Joined: Jan 2003
Posts: 4,391
I
Moderator
Ryan,

Quote
What is unfortunate is that 250.66 (GEC sizing) is driven by the size of service entrance conductors. If the POCO doesn't change their wires, the electrician doesn't have to change the grounding electrode conductors.

You lost me here, even if this is an underground service the electrician replaced the wire from the meter to the panel right?

These are still service entrance conductors and the ground wire size are based on these.

Quote
Service Conductors. The conductors from the service point to the service disconnecting means.

If we sized the grounding conductor to the POCO wire that would be a big change as many times the POCO wires are 4 AWG or 6 AWG, at least for overhead.

Bob


Bob Badger
Construction & Maintenance Electrician
Massachusetts
Joined: Apr 2002
Posts: 7,381
Likes: 7
Member
Iwire: Ithought it was only me that had the same thoughts???

Ya beat me to the post again.

John


John
Joined: Aug 2003
Posts: 1,374
R
Moderator
One of the things I love about these forums is that they keep you on your toes! Thanks for pointing that out to me Bob! I was thinking "service conductors" and not "service entrance conductors"...my bad [Linked Image] The type of change out I usually see is for an underground service and an "all in one" type of panel on the exterior. The only service entrance conductor "wires" you see are the POCO's, as the panel has bussing from the meter to the panel. When that occurs, do you consider the bussing to be the service entrance conductors and assume the equivalant rating of the panel for the size of them? Thanks again for correcting me Bob.


Ryan Jackson,
Salt Lake City
Joined: Jan 2003
Posts: 4,391
I
Moderator
Ryan, I was thinking about this while at work and realized that what I think of as a typical service is not how everyone does it.

I have never seen an all in one setup in this area, and an outside disconnect for a dwelling unit is very rare.

Here is note 3 from 250.66

Quote
3. Where there are no service-entrance conductors, the grounding electrode conductor size shall be determined by the equivalent size of the largest service-entrance conductor required for the load to be served.

It sounds like even if they install a 200 amp panel that they could size the GEC by the calculated load.

In the absence of load calculations maybe just have them size it to a 200 amp conductor?

Glad to help out, sorry if I came across to strong.

Take Care, Bob


Bob Badger
Construction & Maintenance Electrician
Massachusetts
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