220VAC 20amp gang breaker; really 40 amps?

[Mike]

Hello, I'm pretty sure of the answer, but I want to make sure.

I am wiring a 220V compressor unit and the motor has a rating of 15 amps. Do I need to purchase a 20 amp gang breaker (each pole labeled

20) or 10? (each pole labeled 10).

Thanks.

[Mike]

Double pole breakers are rated with a a single value. If your device is

220v at 15A, you need a 20A double pole breaker.

220V comes through one leg of the breaker and returns along the other one. Multiple circuit breakers don't add their capacities, it's more like the "weakest link". If a breaker in the series was 10A it would trip every time your 15A load started.

Mike O'Donnell

[Mike O.]

As an add on to my previous post:

I suppose you could use two adjacent breakers, with their handles physically tied together (I don't know if that's acceptable under code, and it's probably not a good idea anyway even if it is legal).

In that case you would still need 20A breakers since they're in series..

Mike O. (no I'm not talking to myself.. At least not at the moment..)

[Mike]

Thanks for the help folks. I got the compressor wired up with #12 which runs about 20ft to the breaker. And yes, I have a 20amp double pole.

Thanks!