How many #12 ccc in a conduit add still terminate on a 20 amp breaker.

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nolondant

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I have 4 # 12 THHN phase conductors each has a netural conductor, these conductors are dedicated to computers. After ampacity adjustment factors have been applied to these conductors, will I still be able to terminate these conductors on a 20 amp breaker.
 
I have 4 # 12 THHN phase conductors each has a netural conductor, these conductors are dedicated to computers. After ampacity adjustment factors have been applied to these conductors, will I still be able to terminate these conductors on a 20 amp breaker.

What do you think. Let's see a little math then we will help you out.
 
The answer has appeared here numerous times. Like Dennis asked, what do you think the answer is?

Welcome to the Forum. :)
 
>3, <100.
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6 CCC is all you can have because of the 75 degree terminals on the breaker. 7 CCC would only be good for 17.5 amps after derating. You would not be able to terminate a conductor rated for 17.5 amps on a 20 amp breaker. The contractor wanted a more professional opinion. Please help.
 
6 CCC is all you can have because of the 75 degree terminals on the breaker. 7 CCC would only be good for 17.5 amps after derating. You would not be able to terminate a conductor rated for 17.5 amps on a 20 amp breaker. The contractor wanted a more professional opinion. Please help.
Look at T310.15(B)(2). You can have 9 conductors with a 70% reduction. You can use the 90C table for derating. 12 @ 90C is 30 amps. 70% of 30= 21 amps.
 
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