XHHW vs XLPE cable

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Studio11

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I’m a construction project manager in PA. We failed a residential service inspection. The service cable runs from the meter in conduit underground to the main panel which is in the basement of the house. It failed because the electrician used URD cable that’s labeled XLPE. The inspector claims that the the cable must be labeled XHHW if it runs inside the house because the XLPE doesn’t have duel rating. The electrical cable supplier claims that XHHW and XLPE are different names for the same thing.
So I’m trying to find the truth about this, if anyone is familiar with this?
 
From: https://www.prioritywire.com/xhhw.php

XHHW is an alphabetism or initialism which stands for "XLPE (cross-linked polyethylene) High Heat-resistant Water-resistant."


From: https://wesbellwireandcable.com/blog/what-is-xhhw-wire/

Each letter in the acronym for XHHW refers to a different component of its construction:

X: The X refers to cross-linked polyethylene (XLPE) insulation. It provides much of the wire’s toughness and durability, even in very low or high temperatures.
HH: High-heat resistance is important in many different environments. XHHW-2, the modern version of XHHW, has an operating temperature of up to 90℃ or 194°F in both dry and wet environments.
W: Similarly, water resistance is critical for many outdoor applications, meaning this wire can offer high performance in wet or humid locations.
 
So in particular, if the wire only says XLPE, and doesn't say XHHW or one of the other types listed in Table 310.4(A), that's a violation of NEC 310.4.

Cheers, Wayne
 
Studio11 said:
I’m a construction project manager in PA. We failed a residential service inspection. The service cable runs from the meter in conduit underground to the main panel which is in the basement of the house. It failed because the electrician used URD cable that’s labeled XLPE. The inspector claims that the the cable must be labeled XHHW if it runs inside the house because the XLPE doesn’t have duel rating. The electrical cable supplier claims that XHHW and XLPE are different names for the same thing.
So I’m trying to find the truth about this, if anyone is familiar with this?
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The cable supplier is not the same as the manufacturer. The supplier will say anything...they may be correct but I wouldn't trust their call on it. The fact is it must be label with a "W", at least, in the insulation abbreviation

The problem is that"XLPE" is not even listed in the NEC
 
You can have the same issue with USE cable. It is fine direct buried outside, but cannot come into a building. Some variants of these are marked USE - RHW and that would be OK because RHW can come into a building. Got to watch all those little details when choosing conductors and know which markings are in the code book and where they are and are not allowed.
 
Cable manufacturing standards are from UL[Underwriters Laboratories].
According to UL-44 for XHHW-2, XHHW, XHH the insulation may be XL or EPCV.
ANSI/UL-1581 Reference Standard for Electrical Wires, Cables, and Flexible Cords, explains that XL may be XLPE, XLPVC orXLVA.
That means XLPE may be used for XHHW manufacturing.
 
And just to be clear, the inspector is wrong saying that it "must be labeled XHHW if it runs inside the house.". It DOES need to be an NEC approved type and marked as such, but there are other types. Are you sure it's not labeled use-2/RHH-2?
 
Julius Right said:
Cable manufacturing standards are from UL[Underwriters Laboratories].
According to UL-44 for XHHW-2, XHHW, XHH the insulation may be XL or EPCV.
ANSI/UL-1581 Reference Standard for Electrical Wires, Cables, and Flexible Cords, explains that XL may be XLPE, XLPVC orXLVA.
That means XLPE may be used for XHHW manufacturing.
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This is true, but it does not mean that all XLPE insulation material meets all of the requirements for being an XHHW 'interior approved' conductor.

All school buses maybe yellow vehicles but that does not mean all yellow vehicles are school buses.
 
Of course. The manufacturer must follow the UL standard
THERMOSET-INSULATED WIRES AND CABLES - UL 44
 
XHHW is the UL/NEC cable type designation, and the X in that designation means XLPE insulation is used.

XLPE is the material that the insulation is made of; Cross (X) Linked Poly Ethylene. It’s like heat shrink tubing shrunk down to the size of the wire, as opposed to PVC that is a liquid poured over the wire during the manufacturing process of other types of wire such as THHN or TW.

If you have a cable that ONLY says “XLPE” on it and does not show a UL/NEC type designation, you have a mistake. It would be like having THHN that just said “PVC” on it. Totally useless. My guess however is that the printing showing the cable type is just not visible on the short exposed areas. You might look at the other end to see if the UL/NEC printing is visible. The unlikely alternative would be that the cable was bought dirt cheap from someplace like China and has no UL listing.
 
Jraef said:
XHHW is the UL/NEC cable type designation, and the X in that designation means XLPE insulation is used.

XLPE is the material that the insulation is made of; Cross (X) Linked Poly Ethylene. It’s like heat shrink tubing shrunk down to the size of the wire, as opposed to PVC that is a liquid poured over the wire during the manufacturing process of other types of wire such as THHN or TW.

If you have a cable that ONLY says “XLPE” on it and does not show a UL/NEC type designation, you have a mistake. It would be like having THHN that just said “PVC” on it. Totally useless. My guess however is that the printing showing the cable type is just not visible on the short exposed areas. You might look at the other end to see if the UL/NEC printing is visible. The unlikely alternative would be that the cable was bought dirt cheap from someplace like China and has no UL listing.
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There's alot of this URD out there that does not have NEC type designations. Why supply houses carry it is beyond me.
 
Todd0x1 said:
I meant why are they selling URD to electricians who clearly need 'mobile home feeder' (same thing but w/ USE2 and XHHW ratings)
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Most probably because the local electricians are more concerned with material cost than complying with an NEC requirement that is not 'enforced' in their area.

At least, this was my experience during the 16 years I worked for a regional electrical wholesaler. There were many products where we carried both NEC compliant and non-compliant versions of products.
 
jim dungar said:
Most probably because the local electricians are more concerned with material cost than complying with an NEC requirement that is not 'enforced' in their area.

At least, this was my experience during the 16 years I worked for a regional electrical wholesaler. There were many products where we carried both NEC compliant and non-compliant versions of products.
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Interesting. Thanks for the explanation.
 
jim dungar said:
Most probably because the local electricians are more concerned with material cost than complying with an NEC requirement that is not 'enforced' in their area.

At least, this was my experience during the 16 years I worked for a regional electrical wholesaler. There were many products where we carried both NEC compliant and non-compliant versions of products.
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Exactly...the same thing happens with LFMC...around here if you order that from the supply house, you will get the unlisted version and not the listed version that has been required by the code since the 1996 code. One local contractor had to replace over 1000' of it they had used to supply chain hung fixtures in an industrial facility because the inspector caught it.
 
Todd0x1 said:
There's alot of this URD out there that does not have NEC type designations. Why supply houses carry it is beyond me.
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I’m not sure what qualifies as “URD” cable But if it is URD, would this mean that it is acceptable for underground application, but not permitted to come into a house, unless it’s labeled, XHHW?
 
Studio11 said:
I’m not sure what qualifies as “URD” cable But if it is URD, would this mean that it is acceptable for underground application, but not permitted to come into a house, unless it’s labeled, XHHW?
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Others here can likely reply more accurately on this, but basically URD (which is not dual marked) is just listed as USE under UL851 where the dual listed ones (that are XHHW or RHW) are also listed under UL44 which is regular wire.
 
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