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I want to run 2 baseboard heaters on a double pole 30 amp breaker with 12/2 wire. Is that ok?

isherwood
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Larry Cooper
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  • Hello, and welcome to Home Improvement. If an answer is helpful, please click the large check mark next to it to accept. And, please [take our tour](//diy.stackexchange.com/tour) so you'll know the details of contributing here. – Daniel Griscom Mar 03 '20 at 13:34
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    What are the wattage ratings on the heaters involved? What make and model is your breaker panel? – ThreePhaseEel Mar 04 '20 at 01:17

3 Answers3

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No! 12/2 wire is NOT suitable for a 30 A circuit.

While there are other considerations, you will need to use a MINIMUM of 10 AWG Cu wire for a 30A circuit.

Beyond that, whether 30A is enough for your two heaters cannot be answered because that depends on the current requirements for the heaters.

jwh20
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Do the space heaters total less than 3840 watts? Then just change the 240V breaker to 20A, done.

Can't run 12 AWG wire off a 30A breaker, but you probably don't need to. If you're going "Oh, gosh, I already own a 30A breaker", 20A breakers cost ten bucks.

If you're dealing with an obscure panel like Pushmatic where 20A breakers are not ten bucks, then stay with 30A but run 10 AWG wire.

Harper - Reinstate Monica
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No, #12 wire is limited to a maximum of 20A overcurrent protection by NEC 240.4(D)(4).

Generally fixed electric space heating is required to be treated as a continuous load by 424.3(B), so 210.20(A) limits a 20A space heating breaker to 16A, or #10 wire on a 30A breaker to 24A.

NoSparksPlease
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