Direct Burial Conductor...

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1793

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Location
Louisville, Kentucky
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Inspector
I'm looking at converting a 200a Overhead Service to Underground. I'm looking for a conductor that is both Direct Burial and would be Sunlight Resistant as well.

I normally use 4/0 AL URD for Underground but I'm not sure if that is Sunlight Resistant as well. I would be willing to use some other type of wire if anyone has any suggestions.

As always, thanks for your help.
 

KevinVost

Senior Member
Location
Las Vegas
I'm not that familiar with URD, but I would think that it would be listed on the jacket of the wire if it was S/L resistant. Can't you just sleeve it with PVC or other raceway where it emerges from grade? {Art 300.5(D)(1)}
 

1793

Senior Member
Location
Louisville, Kentucky
Occupation
Inspector
I'm not that familiar with URD, but I would think that it would be listed on the jacket of the wire if it was S/L resistant. Can't you just sleeve it with PVC or other raceway where it emerges from grade? {Art 300.5(D)(1)}

This conversion would cause me to run conduit, PVC, up the Utility Pole and at some point, either Drip Loop or otherwise, some of the conductor will be exposed to Sunlight.

I've looked at Article 310 but I'm not sure which insulation types would be DB rated. Enlightenment would be appreciated.
 
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Dennis Alwon

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Location
Chapel Hill, NC
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This conversion would cause me to run conduit, PVC, up the Utility Pole and at some point, either Drip Loop or otherwise, some of the conductor will be exposed to Sunlight.

I've looked at Article 310 but I'm not sure which insulation types would be DB rated. Enlightenment would be appreciated.

USE art. 338 is for db . I bet it is sunlight resistant
 

KevinVost

Senior Member
Location
Las Vegas
This conversion would cause me to run conduit, PVC, up the Utility Pole and at some point, either Drip Loop or otherwise, some of the conductor will be exposed to Sunlight.

I've looked at Article 310 but I'm not sure which insulation types would be DB rated. Enlightenment would be appreciated.

338 for DB. Southwire dual rates their wire with an USE/XPL rating (direct burial I believe) and sun light resistant. I looked at their web site and all their XPL underground ratings are sunlight resistant.
 

jdsmith

Senior Member
Location
Ohio
Tray Cable (type TC) is sunlight resistant, rated for direct burial, and can be used for almost anything- you'll just need an industrial-oriented supplier to sell it in cut lengths.
 

augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
If I recall correctly, true URD is a utility covered conductor and not a recognized NEC insulated conductor (building wire). Southwire's USE is also sunlight resistant.
 

1793

Senior Member
Location
Louisville, Kentucky
Occupation
Inspector
Thanks all for your input. After looking more closely at Table 310.13(A), page 70-143, 2008, in the top corner I found what I was looking for.

I found a piece of URD I've used in the past as well and it is USE rated, I did not see anything about Sunlight though. I'll check with the Supply House in the morning.

Again, thanks.
 

don_resqcapt19

Moderator
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Location
Illinois
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retired electrician
Also don't forget that if the cable is just marked USE, it is not permitted to enter a structure even for termination purposes.
 

1793

Senior Member
Location
Louisville, Kentucky
Occupation
Inspector
I would like to follow up on this thread. I would be hitting the meter can outdoors with this USE/XLP.

My next question, "Where can I find out what size Sch 80 PVC I would need for three 4/0 AL conductors, USE emerging from ground up to the meter can"? The meter is about 5' above grade.

I don't see USE listed in any of the Tables in Chapter 9 or the Annex.
 

charlie

Senior Member
Location
Indianapolis
XLPE is not a NEC insulation type. URD with XLPE on it and without USE on it is not permitted under the rules of the NEC.
I agree 100%. XLPE is cross linked polyethylene and USE is underground residential distribution. We use a lot of Type USE cable and most of it is XLPE and not duel rated or listed cable. :)
 

curt swartz

Electrical Contractor - San Jose, CA
Location
San Jose, CA
Occupation
Electrical Contractor
I would like to follow up on this thread. I would be hitting the meter can outdoors with this USE/XLP.

My next question, "Where can I find out what size Sch 80 PVC I would need for three 4/0 AL conductors, USE emerging from ground up to the meter can"? The meter is about 5' above grade.

I don't see USE listed in any of the Tables in Chapter 9 or the Annex.

For raceway sizing use RHW.
 

charlie

Senior Member
Location
Indianapolis
. . . Where can I find out what size Sch 80 PVC I would need for three 4/0 AL conductors, USE . . .
Use the dimensions given by the manufacturer of the cable assembly. In lieu of that, find out what the dimensions of the individual conductors are and use the conduit fill calculations for the individual conductors. :)
 
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