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#6/2 NM Good for 65 amps?

Posted By: aldav53

#6/2 NM Good for 65 amps? - 06/02/05 08:04 AM

The code book says #6 THHN is good for 65 amps. Is 6/2 NM considered THHN? Its not marked that. How many amps is 6/2 NM good for? At Home Depot they have 6/2 labeled rated at 50 amps. ??
Posted By: plcnewbie

Re: #6/2 NM Good for 65 amps? - 06/02/05 08:28 AM

check out 334.80 ampacity NM is 60 degree rated conductor

[This message has been edited by plcnewbie (edited 06-02-2005).]
Posted By: iwire

Re: #6/2 NM Good for 65 amps? - 06/02/05 09:22 AM

Because of 334.80 6/2 NM is rated 55 amps.

With the use of 240.4(B) many times you can use a 60 amp breaker with 6/2 NM.
Posted By: aldav53

Re: #6/2 NM Good for 65 amps? - 06/03/05 04:56 AM

Couldn't find the code art. 6/2 NM is supposed to be 90 deg rated, which is the same as THHN, which would be 65 amps.
Posted By: gfretwell

Re: #6/2 NM Good for 65 amps? - 06/03/05 05:56 AM

334.80 Ampacity.
The ampacity of Types NM, NMC, and NMS cable shall be determined in accordance with 310.15. The ampacity shall be in accordance with the 60°C (140°F) conductor temperature rating. The 90°C (194°F) rating shall be permitted to be used for ampacity derating purposes, provided the final derated ampacity does not exceed that for a 60°C (140°F) rated conductor.
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