How Does A Double Pole Circuit Breaker Trip?

Question

On my electrical service panel, the "MAIN" breaker is a double pole breaker and each side is marked "100 Amps." Does that mean that when the total amperage exceed 100 one side it will trip, or if the total of both sides exceed 100 amps it will trip? So do can all my appliances together draw up to 200 amps, or just 100 amps? Also, I recently bought a new electric range. I need a double pole breaker because it uses 240 volts, and the total consumption of the range should not exceed 40 amps. Should I get a double pole breaker with 20 amps marked on each side (the whole thing is marked 20 amp double pole breaker) or should I get one with 40 amps marked on each side (the whole thing is marked 40 amp double pole breaker)?

Answer 1

You have a Maximum of 100 Amps total to trip the main breaker. For your new electric range you need a double pole breaker rated at 40 Amps, and used with a minimum of 8 guage copper wire.

When the breaker is sold as a 1 piece breaker (about 2 inches wide) it is rated to the max of the marked amperage.

It is very unlikely to ever draw over the 100 Amps even though all the branch breakers add up to more than 100.

Answer 2

Your main breaker will trip if either side pulls more than 100 amps.  Its actually 2 - 100 amp breakers held together with a clip.  The clip shuts down the side that did not blow so there is no power going to the source that caused the breaker to blow.   You will need a 40 amp 2 pole breaker for your range.

Answer 3

You have a 100 amp main. You need to get a 40 amp double pole breaker 40 marked on each side.