4/0-4/0-2/0-4 urd

[Wastedwagesracing]

If I wanted to run this in PVC conduit what would be the proper size?

 

[oleguy]

min 2".but 2 1/2 would be better.is this for a sub panel?if so can't use it.all current carring conductors have to be 4/0.size reduction is for main service only.now,if you are comming from load side of meter,and not from main panel in house,you are ok.

 

[Charles (in GA)]

Just remember that URD, if it does not carry any other ratings, cannot enter a building, will need to be terminated outside and spliced to something that can enter the building. If it has multiple ratings, such as USE, then it would be OK to enter the building.

Charles

 

[pattenp]

Straight USE can not enter the building because it is not fire resistant rated. It needs to carry the RHH or RHW rating.

Just remember that URD, if it does not carry any other ratings, cannot enter a building, will need to be terminated outside and spliced to something that can enter the building. If it has multiple ratings, such as USE, then it would be OK to enter the building.

Charles

 

[pattenp]

I'm not saying you're wrong but this is the first time I've heard this. I've seen Quadplex/ Mobile Home Feeder with reduced neutral and grounds used to feed sub-panels and pass inspection. What code section prohibits it's use for a sub-panel?

min 2".but 2 1/2 would be better.is this for a sub panel?if so can't use it.all current carring conductors have to be 4/0.size reduction is for main service only.now,if you are comming from load side of meter,and not from main panel in house,you are ok.

 

[pattenp]

After some research I believe the information you have given that the neutral can not be reduced in a feeder to a sub-panel is incorrect. 2011 NEC 215.2 (A) (2) allows grounded conductors of feeders to be sized according to 250.122.

min 2".but 2 1/2 would be better.is this for a sub panel?if so can't use it.all current carring conductors have to be 4/0.size reduction is for main service only.now,if you are comming from load side of meter,and not from main panel in house,you are ok.

 

[Wastedwagesracing]

Okay all good info and questions, thanks. Let me expand a bit on what I'm doing.. I have two services on my property. 200 amp that feeds the house. Then I also have a 400 amp the feeds the out buildings. The 400 amp disconnect is shot and I have one to replace it. This disconnect is fused for 200 amps. Not sure why it was like that 20 years ago when I bought the place. So I want to run this 4/0-4/0-2/0-4 from that 400 amp disconnect fused for 200 amps to a new 200 amp breaker panel in my new shop.

Is this cool or am I going the wrong direction.

I knew that I was not supposed to bring the UDR right into the panel.. But (don't chastise me) I was going to do it anyway. But school me on the right way.

EDIT: I just spoke with our local electrician that is in doing some work in the plant. I asked about bringing the URD into the building. He said as long as it's in conduit it meets the code. He said you just can't have it in free air.

 

[matt151617]

For what it's worth, all the URD I've seen has the RHH/RHW rating.

 

[pattenp]

As long as the URD carries a multiple rating such as (USE-2 RWH-2 RHH) it is fine to run within conduit within the building. If it only has the (USE) rating then it can't be run within the building even if it's in conduit.

"So I want to run this 4/0-4/0-2/0-4 from that 400 amp disconnect fused for 200 amps to a new 200 amp breaker panel in my new shop."

"Is this cool or am I going the wrong direction."

You're okay. Using the 4/0-4/0-2/0-4 is okay as long as it's protected by a 200A breaker.