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#41399 - 08/25/04 05:30 PM two family with two 200 amp panels (overload?)
nov Offline
Member

Registered: 08/08/04
Posts: 70
Loc: New Jersey
I have a two family home with a 200 amp service drop and two 200 amp panels this seems a little off to me because cant the two 200 amp panels draw more than the single 4/0 service drop can supply. My second question is does each panel need a #4 run for the cold water ground or can I run one and jump between the panels

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#41400 - 08/25/04 06:05 PM Re: two family with two 200 amp panels (overload?)
Electric Eagle Offline
Member

Registered: 04/20/02
Posts: 928
Loc: Alpharetta, GA
Do you have a single 200 amp disconnect at the meter or 2 200 amp disco's. If you have 1 disco with 2 200 amp panels, the single 4/0 is OK, although unusual. If you have 2 200 amp disco's then you MAY have a problem. You might want an electrician to actually look at it rather than diagnose by computer.

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#41401 - 08/25/04 06:06 PM Re: two family with two 200 amp panels (overload?)
shortcircuit Offline
Member

Registered: 06/27/04
Posts: 608
Loc: massachusetts
I'd say the 200 amp drop seems undersized...but only if the load of the 2-family is more than the service entrance cable can handle.As for the grounding electrode conductor,I just would run one #4 to the cold water pipe and just tap the #4 above the 1st panel with a burndie and drop into the 2nd panel...don't forget to supplement with 2 ground rods!

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#41402 - 08/25/04 06:11 PM Re: two family with two 200 amp panels (overload?)
iwire Offline
Moderator

Registered: 01/05/03
Posts: 4343
Loc: North Attleboro, MA USA
Check out 230.90(A)Exception No. 3 in regards to the conductor size.
_________________________
Bob Badger
Construction & Maintenance Electrician
Massachusetts

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#41403 - 08/25/04 06:11 PM Re: two family with two 200 amp panels (overload?)
Roger Offline
Member

Registered: 05/18/02
Posts: 1779
Loc: N.C.
Nov, welcome to the forum. Your question is not easily answered without more information.

Read 230.90, and assuming these panels are the service disconnect, take note of Exception No. 3 specifically, which will force you back to article 220.

The water bond can be #6, see 250.104(B)

Roger

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#41404 - 08/25/04 06:14 PM Re: two family with two 200 amp panels (overload?)
Roger Offline
Member

Registered: 05/18/02
Posts: 1779
Loc: N.C.
Dadburnit Bob, you must of beat me by seconds

Roger

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#41405 - 08/25/04 06:16 PM Re: two family with two 200 amp panels (overload?)
iwire Offline
Moderator

Registered: 01/05/03
Posts: 4343
Loc: North Attleboro, MA USA
Yeah maybe, but you included 220 which will be important.
_________________________
Bob Badger
Construction & Maintenance Electrician
Massachusetts

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#41406 - 08/25/04 06:48 PM Re: two family with two 200 amp panels (overload?)
shortcircuit Offline
Member

Registered: 06/27/04
Posts: 608
Loc: massachusetts
Roger...if the cold water pipe is for connection of the GEC then it must be sized according to table 250.66 which would probally be a #4 copper for a 200 amp SE cable and if it were just a metal water pipe bond then it also must be sized according to table 250.66 except as permitted in 250.104(A)(2) and (A)(3)
250.104(B) is for "other metal piping"

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#41407 - 08/25/04 06:59 PM Re: two family with two 200 amp panels (overload?)
Roger Offline
Member

Registered: 05/18/02
Posts: 1779
Loc: N.C.
Shortcircuit, you are correct, my mistake.

Roger

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#41408 - 08/25/04 07:18 PM Re: two family with two 200 amp panels (overload?)
nov Offline
Member

Registered: 08/08/04
Posts: 70
Loc: New Jersey
There are two 200 amp main breaker panels with no disconnect outside. It is a combo meter pan. The lugs in the center definately accept the 4/0 then buss bars feed the meters. It looks like they are suppose to be 100 amp meters. Because the 4/0 SUE cable that feeds the panel from the meter did not fit under the lugs of the meter so someone made the 4/0 fit into the smaller lug by cutting off some of the strands. The lugs on the meters are one piece.

Thank you for the quick response I will read the arctice numbers that were mentioned

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