USE-2 in PVC Schedule 40 conduit

[th111447]

Hi-

I was planning on running 1/0 URD from my house to my pole barn located 125 ft away to install a sub-panel in the barn. I've dug the trench and there is a lot of rock so I'd like to put it in conduit. I'm not an electrician and plan to have my friend (Certified Master Electrician) hook up the sub-panel in the main. I was trying to save money by digging the trench and laying the conduit. My electrician said they did it for years and never had any issues but I've been reading things stating that you should not. My question is, is it ok to put USE-2 wire in PVC Schedule 40 conduit?

I really want to put the wire in conduit and I'm debating on taking it back and getting XHHW but I like the fact of using URD and conduit better. Your advice is much appreciated.

 

[dcspector]

I do not see a problem per NEC 338 and 340 to install USE in RNC

 

[th111447]

So you don't see any issues with putting the USE-2 in Rigid Non-Metallic conduit? To be specific, the wire has the stamped on it:

"Alcan B 110 AWG AL XLPE USE-2 SUN-RES"

I'm glad to hear you don't see any issues with it. Other items I've read seem to state it does not meet code. Look forward to more feedback.

 

[roger]

I agree, no problem with putting USE in RNC or any conduit if the applicable conduit or cable article doesn't prohibit it.

In this case article 338 doesn't nor does 352.

352.22 Number of Conductors
The number of conductors shall not exceed that permitted by the percentage fill specified in Table 1, Chapter 9.
Cables shall be permitted to be installed where such use is not prohibited by the respective cable articles. The number of cables shall not exceed the allowable percentage fill specified in Table 1, Chapter 9.

Roger

 

[petersonra]

If you are going to go underground in conduit use regular wire rated for wet areas.

If you want to use underground cable of some sort, don't waste time and money with conduit of any kind.

I doubt a few rocks is going to hurt anything. If it bothers you get some sand and put a few inches of sand in the bottom of the trench and lay the cable in the sand.

 

[th111447]

I'd prefer to keep the URD calbe I have and just put it in conduit versus the hassle of returning it. If it doesn't cause any issues, I'll do it. I just read some other posts that stated USE-2 rated only wire could not be installed in conduit because of the heat it generates. I was wondering if someone had made a mistake because I know it can not be run inside a building in conduit? Our local building inspector stated it should not be in conduit but I wanted to know why and he had no logical reason. The funny thing is they don't inspect the trench so you could really do what you want?

 

[th111447]

Also, the biggest reason I want conduit is if I ever I have a problem I shure dont' want to have to dig this 125 ft up again. This is the main reason I want to use the conduit.

 

[roger]

What is the load (especially the continuous load) this cable will have on it?

I doubt very seriously you will have heating problem.

Although, if you are going to let other posts or threads influence your decision you should not only consider a different wire type but maybe you should design a way to circulate liquid nitrogen through the conduit.

Roger

 

[th111447]

The load will depend if I have the money to finish the other half later. If I finish half of the barn with heat, air, lights etc. I would estimate potentially 70 amps. If I don't, the load will be very minimal.

At any rate, I'm trying to design it to handle the full 100 amps, that's why I bought 1/0 wire. I wish I could circulate liguid Nitrogen According to my inspector, don't put it in conduit. According to my master electrician put it in to make life easy in the future if something goes wrong. Everybody seems to have a different perspectives. I just want to ensure it's safe. I appreciate your help.

 

[1793]

...I've dug the trench and there is a lot of rock so I'd like to put it in conduit....

How deep?

...My question is, is it ok to put USE-2 wire in PVC Schedule 40 conduit?

What size?

 

[th111447]

2 inch Rigid Non-Metallic PVC
18 inches deep

 

[1793]

... According to my inspector, don't put it in conduit....

Sounds like that is your ANSWER.

 

[th111447]

I find it interesting how the codes vary so much from different localities. I was curious if other people run URD in conduit and it's safe.

 

[roger]

Sounds like that is your ANSWER.

Norb, if this inspector can not cite a code or code article and section, why would his saying no be the answer.

Niether article 338 or 352 prohibits it period.

Roger

 

[th111447]

Roger, thanks for your reply. Do you think I'm over reacting? Should I take the wire back and buy XHHW(inspector's advice) or keep the USE-2 and put it in conduit(Master Electricians Advice)? Again, the inspector does not inspect the trench.

 

[roger]

I would return the USE if there is no penalty and go with the XHHW, but, if there is a restock fee for the return I would use the USE without a second thought.

Roger

 

[1793]

Norb, if this inspector can not cite a code or code article and section, why would his saying no be the answer.

Niether article 338 or 352 prohibits it period.

Roger

I agree, the point I was was making is that between the two, Inspector or Electrician, with the given information, neither had given code to support and this appears to be in the planning or ready to go mode, I would deal with the Inspector.

I know what I want to say but it is not playing out right on the keyboard.

 

[th111447]

Roger and Norb thanks for your help. A couple of last questions. So 1/0 XHHW Aluminum is the recommendation and this has to be conduit, correct? I'm trying to ensure it's resistant to moisture/water and verifying it's not a direct burial wire. Also, 2 inch conduit is plenty large enough for this wire (3 conductor).

 

[Pierre C Belarge]

If you were to look at the conductor type inside of the typical USE sold in this country, it is Type XHHW.
As Roger has stated, the installation inside of the raceway you have choosen is not restricted by the NEC.


Most likely, the heat generated from your expected load will not come close to heat up the conductor itself enough to create any problems... it might not even get warm enough to melt butter...

I would present the inspector with your new found knowledge and see what he might have to say... any good inspector is going to listen, and the better ones will even learn.

 

[1793]

If you were to look at the conductor type inside of the typical USE sold in this country, it is Type XHHW.
As Roger has stated, the installation inside of the raceway you have choosen is not restricted by the NEC.


Most likely, the heat generated from your expected load will not come close to heat up the conductor itself enough to create any problems... it might not even get warm enough to melt butter...

I would present the inspector with your new found knowledge and see what he might have to say... any good inspector is going to listen, and the better ones will even learn.

Well stated.