Expanding Foam Insulation

[infinity]

It says more than two cables. You could conceivably have two-four wire cables and 8 CCC's and still not require derating.

You still have to derate with 8 CCC's, just so happens that normally the result of the deration doesn't require an increase in conductor size - especially when derating a 60 deg termination application while using 90 deg insulation conductors.

I should have been more clear, I was commenting on 334.80 where no derating is required for two cables regardless of the number of CCC's.

 

[kwired]

I should have been more clear, I was commenting on 334.80 where no derating is required for two cables regardless of the number of CCC's.

True 334.80 doesn't require any derating. But 310.15 still does if they "bundled" together

 

[infinity]

True 334.80 doesn't require any derating. But 310.15 still does if they "bundled" together

True, but that and 334.80 are two different requirements. I was merely commenting on latter part of Greg's post #11.