2003年3月17日 · Re: thhw/thhn direct burial i been using XHHW-2 for pretty long time and it work better for underground counducts run compare to straght THHN/THWN series wires due the THHN outer insluation will come apart and break down and get to inside inslulation and can say bye bye wire (sound of zap) in short time i cant say how long and XHHW-2 is more rugged to take it better for that sisuation

2012年5月26日 · XHHW and XHHW-2 (rated 90 Deg C wet or dry) is a far better insulation than THHW/N. THHW is a PVC and the insulation is very thin, easy to damage and in my experience does not hold up well in wet locations, and the insulation can melt. XWWH is cross linked polyethylene, thicker insulation and is direct bury rated.

2008年12月6日 · I want to run 4-#10 wires in conduit underground for about 70 feet. I have got recommendations for both for various reasons. I would like to know from your experience which of the two has failed less in a very wet location to the point of water in the conduit. xhhw is also a popular choice...

2022年1月2日 · In Table 310.16 there are duplicate entries in the 75 degree C column and the 90 degrees C column for 3 types of insulation. THHW, XHHW and XHWN. In Table 310.4(A) THHW and XHHW each have an application provision that limits the ampacity to the 75 degree C column when installed in a wet...

2010年9月27日 · THHN/THWN is smaller and slicker, much easier to work with. XHHW is in my opinion a much more durable insulation but it is tougher and larger.

2003年4月24日 · Re: thhw Respectfully, a close reading of the UL white book will turn up a few items not mentioned here, or glossed over. Point 1: UL's definition of wet location: "Installations underground or in concrete slabs or masonry in direct contact with the earth, and locations subject to saturation with water or other liquids, such as vehicle washing ...

2024年1月10日 · I see NEC table 310.4 A list THHN for DAMP or dry locations but not for wet locations However home depot product description list their THHN for wet locations. I thought wet listed wire had to include a W suffix in its abbreviated …

THWN -XHHW-2 THHW table 310.13 thats what we use never a problem ever . The only problem is getting a true tape in conduits with water it sticks to the inside wall and drys to the inside walls and never wants to come out again.

2021年4月20日 · I a design specifies THHN/THWN-2 then you need to use conductors which meet both requirements. As has been mentioned the requirements for the different ratings are very similar; I've never bought THHN that wasn't also THWN, but depending upon supplier some might be THWN and some might be THWN-2.

2024年4月20日 · Common is THHN/THWN/THW-2 marked conductor. without the -2 it is only rated 90C as a THHN conductor and 75C as a THWN conductor. THHN is not rated for wet locations so you must use the THWN rat