EGC through Attic

ESolar

Member
We have a solar install on the roof with a solar pass through into the attic. The rooftop solid copper #6 transitions to green braided TWHN-2 in the pass through. Can we run the two two-conductor AC cables and the single conductor TWHN-2 ground through the attic space without a raceway/EMT?
 

ggunn

PE (Electrical), NABCEP certified
We have a solar install on the roof with a solar pass through into the attic. The rooftop solid copper #6 transitions to green braided TWHN-2 in the pass through. Can we run the two two-conductor AC cables and the single conductor TWHN-2 ground through the attic space without a raceway/EMT?
Yes, we do it all the time. You can use Romex; a 20A AC solar circuit is like any other branch circuit.

Caveat: Some AHJ's don't like it, so in their territories we just use THWN-2 in FMC rather than fight about it. Choose your battles.

I don't think anyone has had us put an EGC in a raceway; that would just be silly. :D
 
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jaggedben

Senior Member
Yes, we do it all the time. You can use Romex; a 20A AC solar circuit is like any other branch circuit.

Caveat: Some AHJ's don't like it, so in their territories we just use THWN-2 in FMC rather than fight about it. Choose your battles.

I don't think anyone has had us put an EGC in a raceway; that would just be silly. :D
FMC often can't be used as an EGC, you know.
 

ESolar

Member
Yes, we do it all the time. You can use Romex; a 20A AC solar circuit is like any other branch circuit.

Caveat: Some AHJ's don't like it, so in their territories we just use THWN-2 in FMC rather than fight about it. Choose your battles.

I don't think anyone has had us put an EGC in a raceway; that would just be silly. :D
I assume that using the standard two-conductor cable ("Q-Cable" associated with enphase) plus a single TWHN-2 EGC, as opposed to romex, is also OK.
 

jaggedben

Senior Member
I assume that using the standard two-conductor cable ("Q-Cable" associated with enphase) plus a single TWHN-2 EGC, as opposed to romex, is also OK.
That would have to be in raceway such as FMC or EMT. I don't particularly recommend trying to pull Q cable through FMC, or through EMT for any long distance, and definitely not more than one Q-cable in a raceway. A single Q-cable is fine for short hops between arrays (not withstanding the expense of the Enphase plugs) but otherwise I'd pull THWN-2.

I don't particularly like splicing romex to other stuff in a roof j-box. I do it sometimes, say if it's directly to the Q-cable, but usually prefer to run conduit between arrays. Bringing romex into a wet location at all is questionable, it's only borderline acceptable if you sleeve it a short distance through the roof in EMT and then transition immediately to something else on the roof.

Also I would double check the tray cable code sections, since that is what Q-cable is. It's probably fine on the roof where it is arguably being used per manufacturer instructions. When you start going from j-box to j-box inside a building it might not be.
 

ESolar

Member
That would have to be in raceway such as FMC or EMT. I don't particularly recommend trying to pull Q cable through FMC, or through EMT for any long distance, and definitely not more than one Q-cable in a raceway. A single Q-cable is fine for short hops between arrays (not withstanding the expense of the Enphase plugs) but otherwise I'd pull THWN-2.

I don't particularly like splicing romex to other stuff in a roof j-box. I do it sometimes, say if it's directly to the Q-cable, but usually prefer to run conduit between arrays. Bringing romex into a wet location at all is questionable, it's only borderline acceptable if you sleeve it a short distance through the roof in EMT and then transition immediately to something else on the roof.

Also I would double check the tray cable code sections, since that is what Q-cable is. It's probably fine on the roof where it is arguably being used per manufacturer instructions. When you start going from j-box to j-box inside a building it might not be.

We're thinking about using 1" EMT in which case running two Q-Cables and a #8 EGC should not be a problem. The AHJ seems to think that bundling them and running outside of conduit is fine.
 

ggunn

PE (Electrical), NABCEP certified
We're thinking about using 1" EMT in which case running two Q-Cables and a #8 EGC should not be a problem. The AHJ seems to think that bundling them and running outside of conduit is fine.
You aren't concerned about voltage drop in those #12 wires?
 

five.five-six

Senior Member
Yes, we do it all the time. You can use Romex; a 20A AC solar circuit is like any other branch circuit.

Caveat: Some AHJ's don't like it, so in their territories we just use THWN-2 in FMC rather than fight about it. Choose your battles.

I don't think anyone has had us put an EGC in a raceway; that would just be silly. :D
1) In 35 years, I have never seen an AHJ in an attic or crawl space either for that matter.


2) I put EGCs in conduit all the time, sometimes they have to be ran exposed some distance and PVC is cheep and is only required to be strapped every 10 feet and looks 1000X nicer than the other options.
 
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