G
Guest
Guest
can thhw/thhn be used for service entrance conductors in a direct burial installation? This conductor is ok for wet locations so i assume so.
- Status
ron
Senior Member
- Location
- New York, 40.7514,-73.9925
Re: thhw/thhn direct burial
THWN is ok for wet applications, but with protection such as raceway or an approved cable jacket.
THWN is ok for wet applications, but with protection such as raceway or an approved cable jacket.
ron
Senior Member
- Location
- New York, 40.7514,-73.9925
Re: thhw/thhn direct burial
Underground must be in a listed assembly. 338 covers USE identified for underground use, and 340 covers UF which is suitable for direct burial. Straight THWN is not listed for direct burial.
Underground must be in a listed assembly. 338 covers USE identified for underground use, and 340 covers UF which is suitable for direct burial. Straight THWN is not listed for direct burial.
- Location
- Bremerton, Washington
- Occupation
- Master Electrician
Re: thhw/thhn direct burial
xhhw-2 is is use rated. I have seen THHW fail when used in conduit with water in it.
xhhw-2 is is use rated. I have seen THHW fail when used in conduit with water in it.
curt swartz
Electrical Contractor - San Jose, CA
- Location
- San Jose, CA
- Occupation
- Electrical Contractor
Re: thhw/thhn direct burial
Tom, are you sure about that? I use quite a bit of XHHW-2 and I don't remember ever seeing any of it with a USE rating on it. I know RHW-2 is USE rated.
Tom, are you sure about that? I use quite a bit of XHHW-2 and I don't remember ever seeing any of it with a USE rating on it. I know RHW-2 is USE rated.
frenchelectrican
Senior Member
- Location
- Nord'est Wisconsin et Paris France
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
merci marc
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
merci marc
renosteinke
Senior Member
- Location
- NE Arkansas
Re: thhw/thhn direct burial
Bad news, guys...
According to the UL White book, type XHHW, etc., has not been evaluated for direct burial unless the single conductors have also been marked "type USE or type USE-2."
UL White book, 2001, pg. 120. Look under "thermoset insulated (ZKST)," the paragraph with the heading "Submersible Water Pump Cable."
Bad news, guys...
According to the UL White book, type XHHW, etc., has not been evaluated for direct burial unless the single conductors have also been marked "type USE or type USE-2."
UL White book, 2001, pg. 120. Look under "thermoset insulated (ZKST)," the paragraph with the heading "Submersible Water Pump Cable."
frenchelectrican
Senior Member
- Location
- Nord'est Wisconsin et Paris France
Re: thhw/thhn direct burial
opps sorry i misread it what you try to say but i will retract that part i thought i say it was in the pvc conduct not drict burial sorry my mistake please do appect my apogly
merci marc
opps sorry i misread it what you try to say but i will retract that part i thought i say it was in the pvc conduct not drict burial sorry my mistake please do appect my apogly
merci marc
- Status