200A underground service. Prep ahead for electrician

JohnstownFlood · 03-21-2011, 08:28 PM

Garage was built first and a 200A service with feed-thru panel installed there, inside. Soon the nearby new house will be built, and there is a 65-foot underground run of feed for which to plan.

We want to do the right prep work in advance of the electrician coming. The excavator will dig and backfill the trench for the feed but will be long gone before the sparky comes. We've not hired a sparky yet so we cannot ask this question of him.

Should we just pipe the trench with 2" PVC conduit, turn up and above ground at barn end, and through sleeve in foundation wall into crawlspace at house end, and let Mr Sparky fish it and pull wire?

Would he be using something like 4/0 and 2/0 al XHHW when pulling, plus the #4 ground?

Could we instead use mobile home service cable specified for direct burial in 4/0-4/0-2/0-4, pipe it only at the turn-up-and-out at the barn, through the sleeve in the wall into the crawlspace, and leave a coil of enough cable at each end for Mr Sparky to finish? This option would have the service cable direct-buried and not in conduit.

If neither of these, then what is recommended?

joed · 03-21-2011, 09:22 PM

The inspector will want to see the trench before it is filled. You can dig but don't fill it.

JohnstownFlood · 03-21-2011, 09:31 PM

Have never seen an inspector examine an electrical contractor's underground feed work here. Rough-in inside the house, but not the service. Three very large counties in a very sparsely populated area, total population less than 100K in all three.

J. V. · 03-22-2011, 11:21 AM

I recommend you get your electrician (yes get one) and let him tell you what he will allow you to do and how to do it.

md2lgyk · 03-22-2011, 12:46 PM

I don't think 2-inch conduit is large enough. It's been a while since I laid mine for our new house but I'm sure it was at least 3-in diameter.

JohnstownFlood · 03-22-2011, 02:05 PM

Quote:

Originally Posted by J. V.

I recommend you get your electrician (yes get one) and let him tell you what he will allow you to do and how to do it.

. . . what he will allow you to do . . .

The name of this forum is dee-eye-why, and I think that says it all. Where does "allowed" enter the picture here?

joed · 03-22-2011, 02:30 PM

I think what he is trying to say is you may find that many/some electricians will not use a conduit they have not installed themselves. They have no idea how deep, if you glued it, deburred etc. They won't risk their reputations on others work.

jerseystyle26 · 03-22-2011, 02:59 PM

Inspectors dont inspect the trench, its always filled back in by the time they get there.

JohnstownFlood · 03-22-2011, 03:16 PM

Thanks for the replies. Spent some more time on line, researching, and last night spent a few hours with an NEC 2008 Handbook I borrowed from a friend. I'm pretty sure this will work for us, and for whomever we hire to complete the work at the source end (the feed-thru panel) and at the new service end. Of course, I'll run it by the sparky we hire, but it looks to me like this.

There is no inspection of trench or bury here, and we will bury a 2-1/2" PVC conduit run in a trench of required depth. We are capable of good pipe joinery practice, and will make-up all joints accordingly. At the starting end, the pipe will be sticking maybe a foot out of finished grade, hugging the wall. At the new-house end, it will be run through the sleeve we'll have cast into the foundation wall, sealed all around, and poked through just a little.

We'll blow or suck a mouse through the line, string and wire up so as to get ready to pull, and using the right lube, will pull our wire as two 4/0 al, one 2/0 al, and one #4 solid copper, coiling enough wire at each end with plenty to spare for terminal make-up. It's 200A sizing at the feed-thru source, and 200A is what we want at the new load center in the house.

Mr Sparky can slip on the piping, fittings, etc., needed at both ends to finish up, and do his bonding, grounding, terminating, whatever, etc., and call it a wrap when the inspector signs off.

J. V. · 03-23-2011, 12:08 PM

Quote:

Originally Posted by joed

I think what he is trying to say is you may find that many/some electricians will not use a conduit they have not installed themselves. They have no idea how deep, if you glued it, deburred etc. They won't risk their reputations on others work.

Exactly.

Quote:

Originally Posted by jerseystyle26

Inspectors dont inspect the trench, its always filled back in by the time they get there.

How do they know its deep enough? They just trust you in NJ? They check the trench here. I have seen people have dig down so the inspector could measure the depth.

Quote:

Originally Posted by JohnstownFlood

Thanks for the replies. Spent some more time on line, researching, and last night spent a few hours with an NEC 2008 Handbook I borrowed from a friend. I'm pretty sure this will work for us, and for whomever we hire to complete the work at the source end (the feed-thru panel) and at the new service end. Of course, I'll run it by the sparky we hire, but it looks to me like this.

There is no inspection of trench or bury here, and we will bury a 2-1/2" PVC conduit run in a trench of required depth. We are capable of good pipe joinery practice, and will make-up all joints accordingly. At the starting end, the pipe will be sticking maybe a foot out of finished grade, hugging the wall. At the new-house end, it will be run through the sleeve we'll have cast into the foundation wall, sealed all around, and poked through just a little.

We'll blow or suck a mouse through the line, string and wire up so as to get ready to pull, and using the right lube, will pull our wire as two 4/0 al, one 2/0 al, and one #4 solid copper, coiling enough wire at each end with plenty to spare for terminal make-up. It's 200A sizing at the feed-thru source, and 200A is what we want at the new load center in the house.

Mr Sparky can slip on the piping, fittings, etc., needed at both ends to finish up, and do his bonding, grounding, terminating, whatever, etc., and call it a wrap when the inspector signs off.

Sounds like you have done your homework. Good Luck.

jerseystyle26 · 03-23-2011, 05:05 PM

Cuz tha electric digs tha trenches and. backfills them in nj also in pa n de. Never once has an inspector wanted to see tha trench. Only inspectors ive seen check trenches are tha plumbing inspectors.

jerseystyle26 · 03-23-2011, 05:05 PM

Electric utility company*