4/0 4/0 2/0 Al in a junction box. Procedure, please!

Mike out west · 04-05-2011, 02:50 PM

I have a trench I want to fill, and before I fill it I want to install 2" Sch 40 conduit for use by a future house. (The meter and service entrance are currently on the garage.) This conduit may have very large wire due to the distance to the future house, perhaps 4/0 4/0 2/0 Al. Therefore I am terminating it in an 8" junction box on the outside wall of my garage, right behind my breaker panel. The bells of the PVC are heading up toward the junction box, and because of clearance issues it would make more sense to feed the cable through the conduit on this end and pull it from the future house end.

If I was installing the cable while the trench was open, there would be no problem; I could move the conduit out of the J-box, feed it through, then glue it back into the box. But what do I do when the trench is filled, and I can't really move the conduit? And I can't move the box without cutting the conduit going to it, because conduit enters the bottom and leaves out the back, at 90 degrees to each other. What is the procedure for this? Is there a part that is used for situations like this, where I can cut the conduit and glue it back together without moving the cut ends apart? Or is it common practice to cut a big hole in the top of a 3R enclosure to pull cable through, and then seal it up?

frenchelectrican · 04-05-2011, 03:06 PM

If I am reading this right you have actual main load centre at the garage ?? if so the main breaker is single or you have two main breakers ??

The other issue that allready arise I hope you did not buy the 4/0's yet if not you will need full 4 conductors so you will need 4/0-4/0-2/0-2 alum conductors. { the codes do not allow 3 wire feeders after main breaker anymore }

Second thing you have 8X8 box IMO that is a mite small normally I use 12X12 box if you plan to termatie { hook up } and use the polairs connectors they are neater and quicker than old splitbolts et bunch of tape to wrap it up.

I have managed to pull the cables or conductors with box installed as long you have someone push one end and other end pull it and use plenty wire lube to make it easier to pull.

Few case I use the tugger to pull along the way it have a fitting that actually sit on the pipe so that way it will not pull it out of the ground or others ways.

How long the run from the garage to the house if short run that is not too bad.

The best methold is do not install the box at the end when you pull the conductors until you get it done then install the box.

2 inch PVC conduit is pretty much on border line for 4 conductors if short run you may get away otherwise 2.5 or 3 inch is my standard size I run easier to pull it.

Can you tell us what model breaker box you have there ? that will help us a idea how to do this in proper way.

Merci.
Marc