URD direct burial to from house to outbuilding

[Greg1707]

I happened upon this installation. URD with a separate THHW conductor are direct buried in a trench to an outbuilding with a main panel inside the structure. Is this the best option? Is there a USE cable with four conductors available for this situation?

 

[ptonsparky]

The THWN is fine if that is conduit all the way, but not for DB as you've indicated. I've buried a separate USE bundled up with the triplex on occasion

Yes, they make a 4 wire version of what you have but you may need to remark the cable to indicate the EG and Neutral.

 

[augie47]

Note: URD is not an approved NEC wiring method but your picture indicates at least one of the conductors is USE-2 which is approved for direct burial and for use in a conduit.

 

[ptonsparky]

Note: URD is not an approved NEC wiring method but your picture indicates at least one of the conductors is USE-2 which is approved for direct burial and for use in a conduit.

That is a common cabling and marking for the triplex he has pictured. The THWN is the oddball.

 

[augie47]

That is a common cabling and marking for the triplex he has pictured. The THWN is the oddball.

agreed.. I just noticed he referenced it as "URD" and wated to make sure he realized it also had an acceptable rating

 

[kwired]

Since the EGC can (in most cases) be bare copper and still be direct buried, I have no issue with using copper THWN for the EGC here.

I know some will probably disagree.

If that green conductor is aluminum, I say it needs direct burial rated insulation.

 

[Cow]

Since the EGC can (in most cases) be bare copper and still be direct buried, I have no issue with using copper THWN for the EGC here.

I agree.

If a GEC can be bare, I don't know why an EGC can't be buried THWN.

4 wire mobile home feeder may have been a simpler choice for this installation, but I don't know the circumstances.

 

[readydave8]

4 wire mobile home feeder may have been a simpler choice for this installation, but I don't know the circumstances.

Around here, SH's did not stock 4/wire until 15-20 years ago (because "nobody bought it", self-fulfilling statement), so I have seen and done similar installations