What size service wire for new workshop

[dstig1]

URD is used in conduit all the time. It is direct burial rated but conduit provides an extra protection and a pathway for additional line voltage conductors of the same voltage class or replacement if necessary. Also I hope if your running that xhhw underground that its going in conduit. Xhhw is not direct burial rated. With copper wire you could have used thhn which is less expensive and has a wet rating and is permissible in conduit underground. Direct burial copper is called U.S.E.

Actually THHN is not wet rated, but most THHN you find these days is dual rated THHN/THWN The "W" means wet.

 

[747driver]

120ft from house to barn. 420ft of wire? How does that work.

Some reason i couldn't send a private message reply so here is my message. Don't laugh to hard !

Running a ground wire as well as the two live lines and the neutral ??[/QUOTE]

I am running 2 #4 copper wires for live feed and 1 #4 copper for the neutral. Didn't think i would need a ground wire as both service panels are grounded with a ground rod. Now i see that this might not be correct to do. Our place in Tenn. is all run with romex.

I am use to running all my wires in metal conduit as this is code here in Chicago. The conduit serves as the ground wire. So with this said i need to add a ground wire to my run as well...correct ? Does the ground wire have to be #4 copper as well or can it be smaller ?

Thanks for your message as it is well taken advice !!

Chuck

 

[medic0648]

Some reason i couldn't send a private message reply so here is my message. Don't laugh to hard !

Running a ground wire as well as the two live lines and the neutral ??

I am running 2 #4 copper wires for live feed and 1 #4 copper for the neutral. Didn't think i would need a ground wire as both service panels are grounded with a ground rod. Now i see that this might not be correct to do. Our place in Tenn. is all run with romex.

I am use to running all my wires in metal conduit as this is code here in Chicago. The conduit serves as the ground wire. So with this said i need to add a ground wire to my run as well...correct ? Does the ground wire have to be #4 copper as well or can it be smaller ?

Thanks for your message as it is well taken advice !!

Chuck[/QUOTE]

I know in TX metal conduit HAS to have a ground run AND a grounding collar bonded to ground. Might be different in other states. Also wire needs to be de-rated for safety in conduit.

 

[grsthegreat]

Ground wire #6. Nec requires 4 wire run for 220 circuit. You will still need a ground rod at both ends. The shop panel HAS to have an isolated neutral buss and the neutrals and ground MUST NOT be on same bus.

 

[GPintheMitten]

I've never used metallic conduit underground. I doubt that it is allowed due to rust and corrosion concerns.

 

[medic0648]

I've never used metallic conduit underground. I doubt that it is allowed due to rust and corrosion concerns.

There is metallic conduit rated for underground use, usually rigid conduit. PVC conduit gets burned through on long runs due to friction, thus is usually less preferred(except for cost.)

 

[GPintheMitten]

There is metallic conduit rated for underground use, usually rigid conduit. PVC conduit gets burned through on long runs due to friction, thus is usually less preferred(except for cost.)

Ok. I was unaware of this. Thanks.

 

[medic0648]

Most of the pipelines and utilities bury non galvanized metal pipes all the time. Sewers are usually black iron or steel. Same with gas distribution lines. Most water lines are still metallic.

 

[GPintheMitten]

Most of the pipelines and utilities bury non galvanized metal pipes all the time. Sewers are usually black iron or steel. Same with gas distribution lines. Most water lines are still metallic.

Ok.i guess I knew that but I wasn't thinking about sewers and gas mains. I was thinking about buried electric service between a house and an outbuilding.

 

[breadtrk]

Another voice of experience...


Hire a real electrician. Following the advice of a forum may work, it may also result in a fire that destroys everything in there. Good luck with the insurance company if that happens.