URD Choices

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A/A Fuel GTX

A/A Fuel GTX

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WI & AZ
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Electrician
In my area, 4/0 4/0 2/0 URD is used for many underground feeders from a meter pedestel to a panel in a home having a 200A service. I know 4/0 4/0 4/0 URD is also available but seldom used. Is it allowable to downsize the neutral in an underground feed and not in a service with overhead service entrance conductors/feeders? I always see a full size neutral in overhead applications.
 
Aren't overhead service drop conductors usually owned and installed by the utility?

And UG service conductors are owned and installed by the customer - connected at the service xfmr by the utility?

It could be this is a local utility requirement.

When I did my house (and my father's place as well) the utility was adamant:
1. The UG service conductors belonged me.
2. They weren't about to do any temporary connection should they fail during the winter.

Mine went in sized per the NEC (and bumped up for VD) - not the minimal, normal utility size.

I didn't answer your question (cause I don't know the answer), just pointing out the rules may be different.

carl
 
Dennis Alwon said:
You can downsize the neutral as long as you folow art. 250.24(C)(!)
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Thanks Dennis.....I didn't know the code reference pertaining to my question. So in reading 250.24(C) (1), with 4/0 AL phase conductors, I could legally run a #2 AL grounded conductor.
 
m73214 said:
Thanks Dennis.....I didn't know the code reference pertaining to my question. So in reading 250.24(C) (1), with 4/0 AL phase conductors, I could legally run a #2 AL grounded conductor.
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Theres a little more to it than that. You must also calculate the nuetral load in accordance with 220.61. The large of 220.61 and 250.24(C)(1) is your minimum nuetral for a service. After that, 220.61 and 215.2 determine the minimum nuetral.
 
Thanks for the additional comments, Ryan. So in reading the code references, in general, the 4/0 4/0 2/0 AL URD should be more than adequate in most applications.
 
m73214 said:
Thanks for the additional comments, Ryan. So in reading the code references, in general, the 4/0 4/0 2/0 AL URD should be more than adequate in most applications.
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You're welcome. I would assume, once you factor in the range, A/C, water heater or other 240V loads, that it would be fine.
 
m73214 said:
Carl....I'm referring to service entrance conductors, not the service drop.
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You easily convinced me to read all of the art. 100 definitions from Service to Service Lateral. It's clear to me I am an industrial sort. Thanks.

carl
 
Urd

Urd

as a side note, it would be my opinion that a URD conductor could not be brought into the panel in the 1st place. If the cable is rated URD and only URD it would be a covered utility cable and not and insulated building wire.
 
augie47 said:
as a side note, it would be my opinion that a URD conductor could not be brought into the panel in the 1st place. If the cable is rated URD and only URD it would be a covered utility cable and not and insulated building wire.
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In our area URD comes with a USE marking or a USE RHH RHW marking. IN the former case it cannot be brought in to a building, in the latter case it can. The RHH RHW is flame retardant.
 
urd

urd

same here, al. Since dual ratings were not mentioned in the original post. I felt a "flag" might be needed.
 
augie47 said:
as a side note, it would be my opinion that a URD conductor could not be brought into the panel in the 1st place. If the cable is rated URD and only URD it would be a covered utility cable and not and insulated building wire.
Click to expand...

Even if the URD ( not dual rated ) only went into the house a few feet, in conduit of course? If you would not allow that, would you suggest bringing the URD into an exterior mounted J box and splicing a piece of SEU to run to the panel?
 
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Urd

Urd

To me, URD (soley) is a utility product, not an insulated conductor and I would not accept it for anything but POCO installations (over which I have no jurisdiction) . With that said, I have not encountered a sitaution wher POCO brought cables (URD type) into a building.
 
Urd

Urd

Tom, In this area I have seen two "URD" products. One is rated combination URD/USE and I have no problem with it being used as decribed in Art 338.
The other, simply identified as URD, I am told is a covered conductor developed for utility companies as an underground distribution cable and I do not find it listed in Art 310 as an acceptable building wire.
 
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