I have a 200 amp panel below my meter with feed through lugs, which I will connect 4/0, 4/0, 2/0 aluminum to my house 120' away. What size aluminum wire do I need to run for ground? Thanks.

 

#6 copper to a driven ground rod and #2 aluminum XHHW to the house along with the feeder, assuming it is all in conduit. If you are wanting to use direct burial, buy 200 amp direct burial mobile home feeder.

 

Aluminum cannot be used to a ground rod.

 

I don't think I worded my original question very clearly. The panel on my house is a 200 amp subpanel. I know that I need to run 4 conductors--2 hot, 1 neutral, and 1 ground. My local hardware store does not carry mobile home feeder, so I already purchased 4/0, 4/0, 2/0 to satisfy the 2 hots and 1 neutral. What I need is the fourth cable, which I would like to also run aluminum. I planned on USE buried in 2" conduit. I think CasualJoe understood what I was getting at, and recommends #2 aluminum. Is that right?

I planned on grounding the panel to rebar buried in my footing with #4 copper.

If there is anything I am overlooking please let me know.

 

I spoke too quickly, #4 aluminum will work for you since this is a feeder and not the ground to the cold water line. Underground service entrance (Type USE) has has XLP insulation and is typically used for direct burial, it doesn't need to be in conduit. If you do pull it into conduit, you'll probably never get it into 2" conduit. This product comes off the reel with a slight wrap or twist to keep the conductors together for easier handling when burying. That wrap will not easily pull through conduit. If you do use conduit, I'd recommend nothing smaller than 2 1/2", 3" might be better. You have paid premium for the direct burial product, why not just bury it?

 

I am not sure how to use the reply feature, so this is my reply to CausalJoe: The 4/0, 4/0, 2/0 URD only cost me $2.15 per foot, and the #4 USE will cost me less than $0.50 per foot. Did i really pay premium? My run is 120', and at $5.25 for 10' of conduit, I decided to pay roughly $65 for that extra protection. Also, I wouldn't even attempt to pull the cable through that conduit. I will actually lay out the cable, slide one piece of conduit to the center, and then slide conduit from each end and glue them with the wire already run. I understand that this may not be the standard way of doing things, but I ran cable to my barn this way and it worked great.

I also have another question. When my feeder enters my house, does it need to be inside conduit on the interior of the house? The panel is in the basement, and I plan on coming either through or over the concrete wall and then down to the top of the panel. Can I come out of the concrete with a bell end and then just run the cable free until it is connected to the top of the panel? The distance may be anywhere from a couple inches to a few feet, depending on where I decide to come in. Thanks again for your help.

 

USE is not allowed to be used inside as of NEC 2008..

ARTICLE 340 — UNDERGROUND FEEDER A(B) Underground Service-Entrance Cable. Underground
service-entrance cable (USE) shall not be used under the
following conditions or in the following locations:
(1) For interior wiring
(2) For aboveground installations except where USE cable
emerges from the ground and is terminated in an enclo-
sure at an outdoor location and the cable is protected in
accordance with 300.5(D)
(3) As aerial cable unless it is a multiconductor cable iden-
tified for use aboveground and installed as messenger-
supported wiring in accordance with 225.10 and Part II
of Article 396
338.24

 

ray2047 - I am not using it as interior wiring, only to connect to my panel.

 

But you wrote:Once it enters the house it is interior wiring. It is not permitted because of it's fire rating and because the type of insulation sometime used produces toxic fumes.

See also: Electrical Contractor: USE by SE

 

Is this your interpretation of the code, or universally accepted? When romex is run to an outdoor outlet mounted on the side of the house, does it become exterior wiring?

My inspector approved the URD that I ran underground and 5' up the wall INSIDE my barn. Wouldn't that be considered interior in your point of view?

 

A conduit system need to be complete box to box. You cannot stop and run the conductors through the air for the last feet. The NEC also says the conductors get pulled in after the raceway is complete, not slide the conduit over the conductors. The glue may damage the insulation.

 

If it extends beyond the box yes.