# THWN-2 as Service Conductors, Overhead Mast



## jar546 (Sep 15, 2019)

If you were called to inspect a new overhead service that used THWN-2 conductors and where the drip loop was placed at the mast head, you noticed that the clear outer coating of the THWN-2 wire has separated from the insulation and was just hanging, would you approve the installation if everything else was code compliant?


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## jar546 (Sep 15, 2019)

Remember, not all wire is listed or labeled as "sunlight resistant" as required by 310.10(D).  Unfortunately they only have to be listed but are not required to be marked "sunlight resistant."

For example, USA Wire & Cable only lists its Black 1/0 or larger as sunlight resistant.  That means no red or white exposed to sunlight and nothing under 1/0 such as what you would see on a temp service.

SouthWire, however says that their SIMpull THHN/THWN is listed and should be marked for "sunlight resistant" on wire #2awg and larger.

General Cable is the same as USA Wire & Cable with "sunlight resistant" marking for 1/0 and larger in black insulation only.

Republic Wire actually has UL approval giving a "sunlight resistant" rating to all sizes and colors.

There are other manufactures out there so for exposed mast weatherheads,  you need to know what type wire, what color, what size and what manufacturer in order to check for compliance with 110.3(B) and 310.10(D)


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## jar546 (Sep 15, 2019)

Add CME Wire & Cable.  They are listed for Sunlight Resistant SR for all colors sizes #8awg and larger.


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## jar546 (Sep 15, 2019)

Alan Wire (AW) lists their THHN/THWN as Sunlight Resistant for all sizes and colors.


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## e hilton (Sep 16, 2019)

So I m thinking ... regardless of the brand and whether or not it is sunlight rated ... the damaged jacket should be a red flag.


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