6/3 nm-b

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nizak

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Is it code compliant to install a 60amp breaker on 6/3 nm-b cable? The application is an indoor hot tub and the mfg's install sheet says 60amp circuit required. I know with certainty that a 50amp breaker would work, but want to install per mfg spec.
 
Do you know the actual load ??
You might also check the mfg. requirements on grounding. Some call for a full size (same as phase) equipment grounding conductor.
 
Section 240-3(b), Next Higher Overcurrent Device Rating. Where the ampacity of a conductor does not correspond with the standard ampere rating of a fuse or circuit breaker as listed in Section 240-6(a), the next size up device (breaker or fuse) can be used. However, this is only permitted if the conductors do not supply multioutlet receptacle branch circuits for portable cord- and plug-connected loads and the next size up does not exceed 800 amperes
 
This one is revised in Massachusetts to only require 60 degree ampacity when the wire is installed in insulation.

We also deleted the derating for NM through holes...2nd paragraph.
 
The tub ampacity , I believe is less than 50 so you can use art 240.4(B) and put the 6/3 on a 60 amp breaker. I have done this many times in a different application
 
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