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Joined: Oct 2002
Posts: 830
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Is there anything in the code that would prohibit using a 200 amp panel with a 200 amp main breaker as a sub panel that is fed by a 90 amp breaker. The reason I would consider using the 200 amp, is to get the amount of circuits that I need in replacing old fuse panels with one breaker panel. The wire size feeding the old fuse panels is probably #2 as far as I can tell at this point ( wasn't able to identify it completely ) but it is fed from a 90 amp breaker. In the event that the load does get up to 90 amps or so, the outside breaker would trip, so the 200 amp is just really used as a means of disconnect for the sub panel, which I know is not really necessary since there is a main outside, but just for convenience purposes, I am thinking on putting one if I can. House belongs a 86 year old man and the panel will be in the basement. My other option would be to run 125 amp wire maybe and put 125 amp panel that might have barely enough room for the circuits. I don't know if I can get a bigger than 125 amp breaker to fit in the 200 amp panel outside or not. Any input would be appreciated. Normally I wouldn't do it like I mentioned above, but I need more circuits than a 100 amp panel can give me.. Thanks .. Steve

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Joined: May 2005
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I don't know of any violation in that setup. I've heard of inspectors that won't approve it, so check with the AHJ.

Would a Square D QO, 100-amp, 32 circuit panel work for you?

Dave

Joined: Oct 2002
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Dave, that would work great, if I could find one. I haven't ever seen one with that many circuits around here. Thanks Steve

Joined: May 2005
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I've used them ever since they came out, Steve, which was about two years ago. All the wholesalers here carry them, as well as Home Depot and Menards. I think I'm in the only municipality in the area that still allows a 100-amp residential service.

Dave

Joined: Oct 2004
Posts: 135
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Tiger, may I ask why some inspectors will not allow this? It seems to be within code and is not a safety concern. Just curious. Would they allow it if a load calc. was performed? Thanks.

Joined: Aug 2004
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cuttler hammer also has a 30 space 100 amp main breaker panel in there CH line. I think it is a good panel if you cant get the QO also slighty cheaper a my supply house anyway

Joined: Apr 2002
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Steve:
How about a 40 or 42 circuit 225 amp main lug only panel??

You have existing main outside, so a MLO panel is acceptable, unless you want to use the 'main' as a disco.

There is no NEC problems with what you propose.

Also, you should be able to get the CH panel as MLO also.

John


John
Joined: Jun 2005
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I think article 110.3 applies here.

110.3 Examination, Identification, Installation, and Use of Equipment
(A) Examination
(7) Classification by type, size, voltage, current capacity, and specific use

If the main breaker panel you want to use has 200 amp MB rating, and you are feeding it with a 90 amp breaker, then in my opinion this clearly violates current capacity in 110.3(A)(7)

Joined: Apr 2002
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Shockme:

Sounds like you mean having a 90 amp rated panel (if there is/was) on a 200 amp OCP.

MLO panels are commonly used around here for circuit capacity (number of branch OCP devices) 225 amp MLO 40 or 42 circuit panels, with 100 or 125 amp feeds are common.

John


John
Joined: Oct 2002
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Thanks guys for the input. I found out today at one of the supply houses, that they can order me a Seimans 100 amp 30 circuit from about an hours drive from where I live. This will probably be the route I take, if the homeowner want it done. Lowes or Home Depot in my area don't carry anything over a 20 circuit 100 amp panel, and even the supply houses don't. I wished they did though. This is not the first time I've needed more spaces for a "panel change out".. Thanks again .. Steve

On second thought after reading Curt's post, I might use a 200 amp 30/42 circuit main lug panel just in case in the future the main breaker and feeder needs to be changed, the panel will already be there. Would save the homeowner a little if they want to expand any more.. I checked the prices and they are about the same for a 100 amp. 30 circuit main breaker, as it is for the 200 amp main lug.. Steve
[This message has been edited by sparkync (edited 08-05-2005).]

[This message has been edited by sparkync (edited 08-05-2005).]

[This message has been edited by sparkync (edited 08-05-2005).]

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