You are correct on both counts. The NEC doesn't permit any panel to have
more than 42 circuits. 100 amp panels generally have up to 20 circuits. Some
circuits are required to be higher than 15 amp to feed heavier appliances
that will be plugged into their outlets, like outlets in bathrooms and
kitchens



wrote in message
ups.com...
I've what I think are 2 very basic questions.

1. My main electric service panel reads "100Amp" service. But when I
add up the break current of all the existing circuit breakers, it sums
to about 280. I suspect that's because no one will be using the max
of each breaker at the same time. But how does one determine this max
number of breakers you can have in a panel ?

If possible, reference to a code chapter or section would also be
appreciated.

2. Some breakers in the panel are 15Amp while others are 20. Whereas
I can understand one may want to protect a specific piece of equipment
(i.e. furnace, water pump, etc.) with a specific amperage, there
doesn't seem to be any reason to me to protecting the kitchen vs. the
bedroom with a different cutoff amperage. Unless for some reason, the
wire size servicing one area was smaller. Any opinions?

Thanks.