ECN Forum Forums General Topics of the Trade General Discussion Area How many breakers?

The answer is above. I think iwire's post is the answer you were actually seeking.

Think about what is connected to it, and forget about the number of breakers for a minute. If you've got 21 amps on each leg, you will have 21 amps on each leg, period.

Now, split it up however you'd like.
4-15 amp 1 polebreakers with 10.5 amps on each of them.
42-20 amp breakers with 1 amp on each of them.

The panel still sees a load of 21 amps per leg.

Get it? It's the LOAD, not the # of breakers.

[This message has been edited by electure (edited 02-19-2005).]

the amount of breakers has nothing to do with connected load.

Think about it this way, you have a 20 amp single pole circuit feeding receptacles in any given room, you put a recording amp meter on it for an extended period of time and see the peak is 7 amps with an average of 2 amps over this period. This would probably be exaggerated for many circuits, so the face value of an OCPD is not really relative when computing a service or panel feeder.

Roger

Hello Electure, I appologize, we must have been typing at the same time.

Roger

That is the concept behind that pesky term "load diversity". Not all loads will be operating fully and simultaneously. This means you can put (40) 20 amp breakers in a 200 amp, 40 ckt panel.

what you seem to be trying to do is a load calculation.
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