Conduit sleeve on roof

N

nickelec

Senior Member
Location
US
Are sleeves composed of RMC from array to array required to be derated?

2008. Nec here

The way I see it

Table 301.15 (B)(2)(a) says the following Adjustment Factors for More Than Three Current-Carrying Conductors in a " Raceway" or Cable..

To me the definition of a Raceway --An "enclosed"channel of metal ......

To me a "sleeve" being open on both ends is not "enclosed".

What says the forum?

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Going off the top of my head here without refreshing myself on the exact code wording, but isn't there something about a "raceway" is a sleeve if it's not part of a complete system? So I'm thinking say it's 36 in long, I think it is still a sleeve but you would have to derate because of the "bundling" or "without maintaining spacing" for more than 24 in wording. So different code section but same result.
 
"Sleeve" is not defined in 100 but it is mentioned in a number of NEC sections. None of the sections it is mentioned in would apply to RMC between arrays that I can see.
 
pv_n00b said:
"Sleeve" is not defined in 100 but it is mentioned in a number of NEC sections. None of the sections it is mentioned in would apply to RMC between arrays that I can see.
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So are you saying it is required or is not required in your opinion

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Derating is required. (That is, if your sleeve is over 24" long.) Note that the derating requirement in 310.15(C)(1) applies even to 'single conductors or multi-conductor cables not installed in raceways' where spacing isn't maintained. So for this requirement it really doesn't matter if you put your stuff in a 'sleeve' or just ziptie it in an exposed but tightly wrapped bundle. And thus while we can debate ad naseum whether a sleeve is raceway or vice versa when run between arrays, it makes no difference to derating.

electrofelon said:
Going off the top of my head here without refreshing myself on the exact code wording, but isn't there something about a "raceway" is a sleeve if it's not part of a complete system? ...
Click to expand...

You may be thinking of 300.10 but that is irrelevant to the derating question.
 
nickelec said:
So are you saying it is required or is not required in your opinion

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Sleeves are not required by the NEC. I have seen various wraps and mesh tubes used in PV arrays to protect conductors. They can provide protection from abrasion and sunlight but they are not covered by the NEC.
 
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