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david

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690.31 and 338.12

do you guys usually extend the conductors from the PV panels to inverters using USE-2 or are most of those conductors duel listed
 

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electrofelon said:
I dont think I have ever come across USE that wasnt also listed as RHH, thus fine for inside.
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I agree with electrofelon on this one as well.

I think USE-2's rating that forbids it from being used inside is really more of an academic rule, than a practical rule today. It could also have something to do with the history of the product development, that at one point there was some reason why USE wire with no other ratings couldn't be used inside. I don't think I've ever seen USE-2, that isn't also rated RHH/RHW-2.

Additionally, I've also never seen TW or THHN that isn't also rated THWN-2.

PV wire is a "super-USE-2" wire that also passes a flame test.
 
Carultch said:
I agree with electrofelon on this one as well.

I think USE-2's rating that forbids it from being used inside is really more of an academic rule, than a practical rule today. It could also have something to do with the history of the product development, that at one point there was some reason why USE wire with no other ratings couldn't be used inside. I don't think I've ever seen USE-2, that isn't also rated RHH/RHW-2.

Additionally, I've also never seen TW or THHN that isn't also rated THWN-2.

PV wire is a "super-USE-2" wire that also passes a flame test.
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I agree a lot of the use-2 has a duel insulation of RHW-2. I wish that rating had been called out, as DON said he sees a lot Of URD and we see a lot of USE being sold. I am glad it is your feeling most Guys when the call out USE-2 thay actually mean USE-2 RHW-2
 
david said:
I agree a lot of the use-2 has a duel insulation of RHW-2. I wish that rating had been called out, as DON said he sees a lot Of URD and we see a lot of USE being sold. I am glad it is your feeling most Guys when the call out USE-2 thay actually mean USE-2 RHW-2
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The word you are looking for is dual, not duel. I think lightsabers might be built using duel-rated wire.

In any case, you do bring up a good point that drawing sets should always call out product identifiers by all terms that are required for the application. Or at least, the most stringent of the terms that would govern product selection.

If pure USE-2 is unacceptable, don't call out "USE-2" and expect that the contractor will end up getting USE-2/RHH/RHW-2. Even though it is the industry norm, and you can likely expect that it will be rated as such.
 
Note that Solaredge systems are ungrounded and this calls for PV-wire and not USE-2 for expose conductors, under present and past codes.

(However, the 2017 NEC will evidently relax this restriction and allow USE-2 again.)
 
Carultch said:
I agree with electrofelon on this one as well.
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Currently yes, very easy to source USE/RHW.

However, that was not the case when I did the first solar job for the company back in 2008 or so. At that time USE/RHW in 10 AWG was a special order in this area and took some time to get.

Before PV came along the only use of USE in this area was underground service and feeder conductors. As such there was no need to be rated RHW and there was no reason for it to have a flame test performed and to pass that test.

To be listed as RHW it has to pass a flame test.
 
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