Sunlight Resistant

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Cody K

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Texas
I am looking for a conductor insulation (not cable) that is listed or labeled sunlight resistant to be used in a cable tray. I am hoping to be able to use the free air table (310.17) which would save money on copper.

The kind of project is a parrallel feed for a 2000 service into an MCC via cable tray using 12-350mcm conductors (if I can use free air table).

Any input would be appreciated. My thoughts are that any tray cable, even single conductor if they make such a thing would have to be sized in table 310.16 because it is a cable. However if I find a conductor such as maybe xhhw-2 that could be used then that would be great. Could xhhw be used in this situation?

Thanks
 
So would it be fine if we use this for feed to MCC? I got some bad looks when mentioning this, their opinion is only use tray cable.
 
don_resqcapt19 said:
Yes, but there is no need for THHN to be sunlight resistant as it can't be used outside.
Click to expand...

Ok, typically on a day to day basis we use thhn/thwn-2 and I dont see where it is labeled sunlight resistant. Talking with our electrical rep he says that xhhw would be a good choice because of its rubbery type insulation and that it is listed sunlight resistant (not sure but that is what he said).

Looking at the code reference to 392.11 (B)(3) it seems we would be ok to rate using table 310.17 (free air) if we space the cables correctly. Do you agree?
 
I have seen THWN that is marked sunlight resistant. Note that per 310.8(D) the conductors that are listed as sunlight resistant are not required to be marked as such. You need to look at the cut sheets for the brand of wire you will be using.
Yes, you can use Table 310.17 if you make the installation per 292.11(B)(3).
 
SUN RES is not necessarily insulation specific. In other words, you can have XHHW that is SUN RES, and you can have XHHW that isn't. Depends on the exact type of compound being used.

I was told once (I can't back this up with code off the top of my head) that if there was any way that any part of the cable could be exposed to sunlight that the whole cable had to be sunlight resistant. If this is true, you would have to consider whether your run passed by a window or skylight.
 
Cody K said:
Ok, typically on a day to day basis we use thhn/thwn-2 and I dont see where it is labeled sunlight resistant.
Click to expand...
This isn't a real good pic, but you can make it out on this piece of #2:

thhnbackside3.jpg
 
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