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#82471 - 11/16/02 06:55 AM 400 amp 120/208 v 3 phase service
elecbob Offline
Member

Registered: 08/23/02
Posts: 142
Loc: WA
I want to feed 2-200 amp 120/208 volt 3 phase panels from a 400 amp CT enclosure. The local utility does not allow me to install a second tap in the CT enclosure. Normally I would install a bus gutter and tap off there, but here I have a space restriction. A salesman at my wholesaler showed me some connection block that have a terminal rated for 500 KCM on one side and 2-4/0 on the other. The AL terminal is mounted on a plastic block and has plastic sides that interlock with other similar blocks.
Could I install 4 of these puppies in an 18' by 24' can rather than using a bus gutter? If It is allowed what are the minimum clearances from the sides of the can?
Thanks
Bob

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#82472 - 11/16/02 08:11 AM Re: 400 amp 120/208 v 3 phase service
spyder Offline
Member

Registered: 10/14/02
Posts: 211
Loc: Massachusetts
Do you have to use a CT cabinet? Why can't you use a standard 400 amp meter socket (320amp continuous and 400 amp intermitent)and use double barrel lugs on the load side connection?

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#82473 - 11/16/02 10:05 AM Re: 400 amp 120/208 v 3 phase service
caselec Offline
Member

Registered: 04/14/02
Posts: 557
Loc: San Jose, CA
Elecbob

Do you want to tap off the load side of the C.T.'s for these 2 panels or are you trying to tap off the line side for 2 additional meters? Are there already load wires connected or would your 2 panels be the only load? I'm just trying to get the whole picture in my head.

Spyder - Do they make 3 phase class 320 meters?


Curt
_________________________
Curt Swartz

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#82474 - 11/16/02 10:20 AM Re: 400 amp 120/208 v 3 phase service
spyder Offline
Member

Registered: 10/14/02
Posts: 211
Loc: Massachusetts
Its been a while but as far as I know they do.

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#82475 - 11/16/02 11:23 AM Re: 400 amp 120/208 v 3 phase service
elecbob Offline
Member

Registered: 08/23/02
Posts: 142
Loc: WA
Either 320 metering or 2 taps off the load side of the ct's is only allowed for residential here. This is commercial so no can do.I need 2-200 amp 3 phase panels. I need to make the tap outside the ct can.
I was wondering if there is an alternative to the bus gutter.
Thanks again.
Bob

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#82476 - 11/16/02 11:55 AM Re: 400 amp 120/208 v 3 phase service
caselec Offline
Member

Registered: 04/14/02
Posts: 557
Loc: San Jose, CA
Bob

Are you saying that your utility does not permit parallel conductors on the load side of the meter for 400 amp services? It is pretty common to use two sets of 3/0 to feed a 400amp panel. For this project you would have the same number of cables in the CT cabinet but they would run to two separate panels instead of one panel.

Curt
_________________________
Curt Swartz

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#82477 - 11/16/02 12:40 PM Re: 400 amp 120/208 v 3 phase service
spyder Offline
Member

Registered: 10/14/02
Posts: 211
Loc: Massachusetts
Is this a new service or an exisiting one/

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#82478 - 11/16/02 05:13 PM Re: 400 amp 120/208 v 3 phase service
elecbob Offline
Member

Registered: 08/23/02
Posts: 142
Loc: WA
Yes they allow parallel runs. But not to 2 seperate disconnects. This is a new service. Seattle City Light's meter division made the rule. A stupid one in my opinion.
Bob

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#82479 - 11/16/02 05:38 PM Re: 400 amp 120/208 v 3 phase service
spyder Offline
Member

Registered: 10/14/02
Posts: 211
Loc: Massachusetts
What about a 400 amp main switch and tap out of that to your two panels or set a 400 amp main distrubution panel. I realize both of these suggestions will add to equipment costs.

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#82480 - 11/16/02 10:59 PM Re: 400 amp 120/208 v 3 phase service
Jacuzzi Guy Electric Offline
Member

Registered: 10/25/02
Posts: 33
Loc: Dearborn Heights Michigan Unit...
Ok, so you have a "space restriction" I imagen that is going under the CT. What I would do is put a 18x24 On the side of the cabinet and run 4" from the CT to the 18x24 and 2" pipe to each of the Panels.

Then into the 18x24 use four split bolts big enough to fit in The big wire and two of the 3/0 for the panels. and feed your Panels from that.

I've done this in the past, and found out that it will pass inspection and is more cost efficient.

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