Supply Wire Rating For Wall Fixture


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Old 10-17-15, 04:02 AM
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Supply Wire Rating For Wall Fixture

Can I install a wall fixture requiring 75 degree C supply wire, using 600 Volt 12/2 NM-B romex rated for 90 degree C but with conductors rated for 60 degree C ampacity?
 
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Old 10-17-15, 05:56 AM
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I don't understand the last part of your question. No such thing as
conductors rated for 60 degree C ampacity?
The only conductors in the box would be the NM-b rated 90° and the fixture conductors which should be rated for at least 75°.
 
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Old 10-17-15, 06:17 AM
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ray2047....here is what I found on the spec for the wire.

Type NM-B (nonmetallic-sheathed cable) may be used for both exposed and concealed work in normally dry locations at temperatures not to exceed 90˚C (with-Ampacity limited to that for 60˚C conductors) as specified in the NEC 1.

I am confused by the 60˚C conductors as stated above when the fixture indicates that it needs 75˚C supply wire??

Thanks for helping out!
 
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Old 10-17-15, 06:26 AM
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That just means older NM-b was rated for 60°and newer NM-b wire is rated for 90° but when they changed the temperature specification they didn't change the maximum amps the wire could handle. Maximum amps for #14 is 15 amps regardless of if it is older 60° wire or newer 90°wire.
 
 

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