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shadowx360 07-09-2008 12:13 PM

How Does A Double Pole Circuit Breaker Trip?
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)?

fw2007 07-09-2008 01:54 PM

If current exceeds 100A through either leg of the 220V line, both sides will trip together.
So, you can draw up to 100A on each side, and that current can be a combination of 110V appliances on one leg, or 220V appliance on both legs.
Both poles of a double pole breaker will always trip together if current through either leg exceeds the rating.

For your range, if the specs are 40A at 220V, you need a 40 Amp double-pole breaker.

Hope this helps


jrclen 07-09-2008 02:44 PM

A double pole breaker is the same as two single pole breakers connected together. So your 100amp 2 pole is 2 100 amp breakers side by side. If either side conducts more than 100 amps the entire unit will trip or open. Both sides will shut off together

That breaker can supply 100 amps of current at 240 volts. It can supply 200 amps of current at 120 volts. Or any combination of the two as long as neither one exceeds 100 amps.

If your range requires a 40 amp 240 volt circuit, then each side of the 2 pole breaker will be 40 amps.

A home type electrical service consists of 2 legs of power at opposite polarity. Between the 2 legs there is 240 volts of electricity. Between each leg and the service neutral conductor, there is 120 volts of electricity.

If you have any questions, just ask away.

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