12-3 wire into a 20 amp breaker


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Old 12-15-11, 03:59 PM
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12-3 wire into a 20 amp breaker

I have a heavy 12-3 wire that i want to put into a 20 amp breaker. Where do i put the black and red wire? white and ground but what to do with the other two? the breaker i actually one of the type that has the two switches on the same breaker
 
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Old 12-15-11, 04:22 PM
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Are you trying to connect to a 240 volt load or run multiple 120v circuits?

one of the type that has the two switches on the same breaker
Do you mean a 240v 2 pole breaker or a tandem set of 120v breakers

Your post is confusing. Please give more detail on what you are trying to do.
 
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Old 12-15-11, 04:54 PM
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its a tandom 20 amp its simply a dedicated line for heater
 
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Old 12-15-11, 05:21 PM
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If this is for a 240 volt heater you will need a full size two pole breaker, not a tandem.

A tandem breaker cannot share a neutral between the two hots. It will overload the neutral.
 
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Old 12-15-11, 05:30 PM
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it's for a simple small space heater. i was hoping to hook this dedicated to one half the tandom as it's dedicated then the other half of the tandom to a couple of lights. a two wire set up a no brainer, 12-2, but the `12-3 wire was free!
 
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Old 12-15-11, 05:41 PM
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As long as the heater is 120 volt you would just use the black and the white. Cap the red at both ends. You may want to label it as unused.
 
 

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