4 conductor URD

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electrofelon

electrofelon

Senior Member
Location
Cherry Valley NY, Seattle, WA
Occupation
Electrician
Hi all, We were planning to run a four conductor URD set directly buried between two buildings (one building supplied form another). Apparently no one stocks this around here so i suggested to the other electrician Im working with that we just get a single piece of USE and bury it right along with a piece of three conductor URD, or lay 4 individual USE conductors. He said that he asked the inspector about that and she said not acceptable because it needs to be a factory assembly. Is there a NEC section that addresses this? I couldn't find one. Thanks,

Ethan
 
Re: 4 conductor URD

300.3(B) Conductors of the Same Circuit. All conductors of the same circuit and, where used, the grounded conductor and all equipment grounding conductors and bonding conductors shall be contained within the same raceway, auxiliary gutter, cable tray, cablebus assembly, trench, cable, or cord, unless otherwise permitted in accordance with 300.3(B)(1) through (B)(4).
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I'd say so long as the conductors are in the same trench, in close proximity, you're compliant. (I bolded the "or" to make it clear the section is calling for at least one method of compliance.)
 
Re: 4 conductor URD

George,
I don't agree. If you are using a cable or raceway, then all of the circuit conductors must be in the same raceway or cable. If you are using single conductors, then the conductors must be in the same trench.
Don
 
Re: 4 conductor URD

But if he is using URD which is triplexed single conductors, is it a cable or single conductors?

Also, they do make quad URD. I'm surprised you can't find it.
 
Re: 4 conductor URD

Don, even with the "or"?

What about 250.134(B)? "...or otherwise run with the circuit conductors." It seems as though the EGC can run alongside the URD.

bdarnell, I recently learned that URD is definutely listed as a cable assembly. :)
 
Re: 4 conductor URD

you didnt mention your load requirements, however if your calculations call for 4/0 I would consider simply using 200amp Mobile home feeder, or 100amp (depending on load) both are widely available in any area...about $2.20/ft here in SC
 
With the clocks resetting, I'm bumping this thread. I hope Don will comment on the "or" comment above.

I think that it may be their intent, but with the wording...
 
Since the conductors were listed as individual conductors prior to the factory combining them into a cable assembly, and are marked according to article 310, isn't it reasonable to consider them 4 individual conductors?

You could take one of the conductors outof the cable assembly, and use it as a single conductor. It's appropriately constructed and marked...
 
Not trying to bend it 'til it breaks, just trying to flex it around a bit and see how much it stretches. :)

Am I that far off base? It's considered a minor (and hard to substantiate) offense to some to strip the sheathing off romex and use the conductors in flex. Those conductors aren't marked according to 310, hence the violation. (Or, at least, the only one I can come up with.)

So, is it so evil to consider that principle for this purpose?
 
George,
I don't know what the "or" means. Maybe for when individual conductors are installed in a trench or a cable tray.
Don
 
Can you get RR?
It's usually less expensive.

I would recommend running conduit, if possible.

Last I checked a RR (railroad) was quite expensive. I agree with running conduit. I hate it when something happens and things have to be dug up again. At least with conduit you have a chance of pulling new wires.

Now what is RR? :?
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