View Full Version : Outdoor Conduit Conductors

02-18-2009, 08:07 PM
I'm fixing to do a panel swap (will be permitted and inspected to 2005 NEC with 2008 provisions, i.e. AFCI) from an old Federal Pacific fuse panel to a Square D breaker box. House is currently BX and some MC from new installs. NM is not allowed per city ordinance.

The reason for the swap is the previous homeowner's handywork and simple age. The panel is a mess and the disconnect for the AC is wired directly to the service entrance lugs. I'd like to do the new run to the AC condenser with THWN in schedule 80 PVC. However, I've also seen XHHN mentioned for use. Is one more appropriate than the other?

02-18-2009, 08:26 PM
Do you mean XHHW instead of XHHN?

The THWN has a thinner jacket is for wet locations which the 2008 clarifies inside pipe outside as a wet location.

Dont see a XHHN listing in the NEC

There is a listing for XHHW which is also listed for wet locations however the outer jacket is thicker than THWN.

THWN is most likely easier to pull and handle both good conductors for your purpose.

02-18-2009, 08:55 PM
That's what I meant. Will use THWN pending approval of plan. Thanks.