NEC attic temperature adder?

[robbiepena]

Does the NEC state anything about derating conductors for attic temperatures? perhaps an adder to the ambient high temp?

 

[jaggedben]

I don't think the NEC says anything about attics but the temperature adjustment requirement is broad and if the attic has a higher temp than outside you should use the attic temperature.

 

[ramsy]

Yes, since table numbers & codes sections change between code cycles, the table for Ambient Temperature Correction Factors Based on 30°C is used to adjust ampacity for attics based on the 10ft - 10% rule.

Attics are measured up to 200 deg.F, with one rule of thumb being a 170 deg attic when its 100 degrees outside.