urd?

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jcole

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Lawrenceburg, Kentucky
Why isnt urd listed in art. 300 of NEC? Is it listed somewhere else or is it called something else? The reason I am asking is because inspector told me I could not use it for a temp pole or service entrance conductors. Thing is Ive always used it on my temp poles. So I come home to look up uses permitted but seems not to be in code. All replies appreciated.
 
The conductors used for NEC installations must be listed and described in the NEC or you can not use them.

Is this 'URD' marked along it's length with the information required by 310.11?
 
Bob

Just a comment on URD. The URD I see and use is also marked RHH/RHW-2. I use it for temp poles and bring it up into meter bases. Never had a problem with the inspectors. As I remember, it stands for underground residential distribution.

Buck
 
Thanks guys. The inspector said it was not listed to be used in conduit. One more clarification please. Is urd and triplex the same thing or are they two different conductor types?

Iwire, I dont remember seeing any labeling? Ill have to check. Thanks again.
 
Most of the URD that I get is also marked XHHW. The URD that the utility has doesn't have any markings, so it would be unsuitable for an NEC install. You'll also see some URD marked "Mobile Home Feeder Cable", but nearly always also says XHHW/RHW, etc.

Triplex is not URD. More commonly called ACSR. Completely unsuitable for below grade work, and not compliant for use in an NEC raceway. Typically not marked with any conductor insulation type.
 
buck33k said:
The URD I see and use is also marked RHH/RHW-2.
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Yes I understand that is possible and in that case could be found in T310.13 :)



bring it up into meter bases.
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That application is not normaly under NEC jurisdiction, that would be under utility control. :)
 
All the URD I've encountered is a twisted assembly of type USE conductors, and as such is eligible for direct burial use, installation in conduit, service mast heads, terminations into meter boxes, service equipment, etc.

XHHW is commonly used in type SE cables, which is not listed for burial.
 
mdshunk said:
SE isn't, but XHHW sure is.
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Where do you get that information from?

From this website I offer the following description of XHHW:

APPLICATION
General purpose wiring designed for power distribution and branch circuits in residential, commercial, and industrial buildings in conduit or approved raceways. Maximum conductor temperature or XHHW is 90?C in dry locations and 75?C in wet locations. Conductor is rated 600 volts.
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nowhere does it say for direct burial use here.


As a comparision, the description of USE from the same website reads a bit differently:
APPLICATION
Type USE or RHW or RHH conductors are used in air, conduit or other approved raceways as specified in the National Electrical Code. USE or RHW or RHH can be used as underground service entrance cable, for direct burial at temperatures not to exceed 75?C; or when used as RHW conductor, temperatures are not to exceed 75?C in wet locations; or when used as RHH in dry locations, conductor temperatures are not to exceed 90?C. 250 MCM and larger sizes may be installed in tray per NEC Article 318. Conductor is rated 600 volts.
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emphasis added.

 
My point is that URD is usually installed direct buried. But I have never seen XHHW marked on the conductors of a URD assembly. I have seen them marked USE however ...
 
kbsparky said:
My point is that URD is usually installed direct buried. But I have never seen XHHW marked on the conductors of a URD assembly. I have seen them marked USE however ...
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XHHW, among other markings. There's usually a whole list.
 
kbsparky said:
Must be brand-specific. Now I'll have to go look again in the shop and make note of the "list" .... :grin:
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I know. I know I have a piece of 100 amp URD on the truck at this very moment, but I didn't drive it home today. Now I wish I did. It's these finer points you never pay much attention to that don't really matter until someone brings up a discussion about it. Now I'm really curious to read some wire. I guess there are worse vices.
 
My understanding is tha "URD" is a utility term for "underground residential development". In our area we refer to direct burial cable "USE" as "URD". "triplex", and "sweetbriar (if it is 4/0)" There is often several labels on this product. Such as "USE/ XLPE"
 
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