100 amp, 42 circuit panelboard

[michellesackett]

Is there a code code requirement restricting a 100 amp panelboard to less than 42 circuits?

 

[Dennis Alwon]

Not since the 2008 NEC. Sq. D makes 60 cir residential panels.

 

[templdl]

Not since the 2008 NEC. Sq. D makes 60 cir residential panels.

They must accomplish this through the use of duplex breakers.
Would it be 30sp and 60 poles 36sp and 60poles?
Or are would they be going with 42/60?
Personally I think it's much better than adding a subpanel.

 

[curt swartz]

They must accomplish this through the use of duplex breakers.
Would it be 30sp and 60 poles 36sp and 60poles?
Or are would they be going with 42/60?
Personally I think it's much better than adding a subpanel.

All of the larger than 42 circuit load centers I have seen utilize some twin breakers. With all of the current AFCI, GFCI & Handle Tie requirements I think they should stop producing load centers with tandem breaker provisions and just have full size provisions.

Panelboards can easily be obtained now with more that 42 circuits in a single box. I just picked up a 72 circuit panel yesterday.

 

[curt swartz]

While the NEC does not have a limit to the number of circuits I believe UL did based on the amp rating of the buss. I read a requirement many years ago that limited the breaker spaces to 10% of the buss rating. If you look at the standard panels available now they pretty closely follow that. A 100 amp single phase panel was allowed 20 spaces (10 per buss), A 125 amp panel was allowed 24 circuits (12 per buss). A 200 amp panel was allowed 40 spaces (20 per buss). A 100 amp 3 phase panel was allowed 30 circuits (10 per buss).

I have never seen a 100 amp 42 circuit load center. If you need 42 circuits you are stuck getting a 225 amp load center. If your load is only 100 amps there is nothing wrong with feeding the 225 amp load center with 100 amps.