XHHW

[augie47]

This thread, https://forums.mikeholt.com/threads/load-side-of-the-service-in-the-attic.2554074/#post-2585816, made me wonder,
Since the Code allows XHHW on rooftops in 310.15(B)(3)(c) without the "adder", have the CMPs ever given thought to allowing XHHW
in areas such as attics without having to make an ambient adjustment ?

 

[Dennis Alwon]

Good question. How could they do that.... They would have to exempt it under many conditions except when temps got above whatever it is that the insulation is rated for.

 

[augie47]

agree,,, just surpriosed that has not come up at the CMP meetings.

 

[infinity]

Currently there is no exception for XHHW in attics so the normal ampacity adjustments are required.