DC wiring in the attic - 2 roof penetrations - visible/not visible

[Ne0eN]

Here's my situation: I'm running two strings from the array through an attic down to a SolarEdge inverter in the garage (roughly 100' run), and the arrays are on two different roof planes. One roof plane penetration is easily accessible from the attic and I intend on using a junction box and EMT conduit down to the inverter in the garage. The second roof plane penetration is about 4' from the attic in an inaccessible location - although I should be able to fish wires to it. Running an EMT conduit is probably not going to be possible. What are my options in this situation? Can I just run PV wires to the most accessible point in the attic (junction box) and then transition to THWN-2 inside EMT?

Next issue will be punching through to the garage via the attic floor between the walls. Again, does the EMT need to be continuous or there is some other method that's NEC code compliant? Inside the garage I will probably use PVC or EMT to the inverter.

I appreciate your input.
-Rob
Reston, VA

[solarix]

A) - can't use PV wire inside the house or attic cause its not smoke rated. Put a junction box under the array and transition to THHN wire there.
B) - regular building wire (Romex) is okay for the solar AC once you are in the house. (We use EMT everywhere, but that is just us)
C) - you can run the wire over the roof if it is in EMT conduit. Looks like heck, but that is what SolarCity does all the time.

[Ne0eN]

A) - can't use PV wire inside the house or attic cause its not smoke rated. Put a junction box under the array and transition to THHN wire there.
B) - regular building wire (Romex) is okay for the solar AC once you are in the house. (We use EMT everywhere, but that is just us)
C) - you can run the wire over the roof if it is in EMT conduit. Looks like heck, but that is what SolarCity does all the time.

A) I'll be using something like SolaDeck Flash Pass-through box so I could transition to THWN-2 wire on the roof. Can I still route THWN-2 wire without conduit inside the inaccessible attic portion?
B) In my case it's DC not AC - SolarEdge micro inverters.
C) It's my own house, I really don't want EMT conduit visible.

[ButchDeal]

A) I'll be using something like SolaDeck Flash Pass-through box so I could transition to THWN-2 wire on the roof. Can I still route THWN-2 wire without conduit inside the inaccessible attic portion?

should be in metal conduit.

B) In my case it's DC not AC - SolarEdge micro inverters.

SolarEdge Optimizers not micro inverters. If they were micro inverters then you would have AC, but SolarEdge uses optimizers so it is DC.

C) It's my own house, I really don't want EMT conduit visible.

you could try to pass flexable metal conduit to the SolaDeck, or use it on the roof for as short a distance as possible. Paint to match the roof as well.
It is pretty much your only choice, in the attic or on the roof. If you can't get it in the attic, then on the roof is all that is left.

[Ne0eN]

should be in metal conduit.


SolarEdge Optimizers not micro inverters. If they were micro inverters then you would have AC, but SolarEdge uses optimizers so it is DC.


you could try to pass flexable metal conduit to the SolaDeck, or use it on the roof for as short a distance as possible. Paint to match the roof as well.
It is pretty much your only choice, in the attic or on the roof. If you can't get it in the attic, then on the roof is all that is left.

Yes, I meant optimizers, the point was that it's DC not AC.
I think flexible metal conduit will be my first choice. Thanks!

[foo1bar]

Here's my situation: I'm running two strings from the array through an attic down to a SolarEdge inverter in the garage (roughly 100' run), and the arrays are on two different roof planes. One roof plane penetration is easily accessible from the attic and I intend on using a junction box and EMT conduit down to the inverter in the garage. The second roof plane penetration is about 4' from the attic in an inaccessible location

How in-accessible?

Can you crawl over to it if you break out some sheetrock in the garage or something?
If so, that's what I'd do.

If it's see-able, but not crawl-able, maybe you can do EMT easier than fishing wires or fishing flexible metal conduit. You can potentially bend a 90 to go up through roof. Then because it's fairly rigid you can push the conduit out in front of you and into place and then up out through a hole.

OR you can run conduit on the roof for 4' so that it's at a point where you can drop through into an easier to handle space.

[solarix]

Yes, you may use Flexible Metal Conduit in the attic and walls for the DC run. Needs to have reflective labels on it identifying it as a "photovoltaic power source"

[foo1bar]

Yes, you may use Flexible Metal Conduit in the attic and walls for the DC run. Needs to have reflective labels on it identifying it as a "photovoltaic power source"

I thought for a solaredge system that isn't actually required by code.
But probably a good idea - easy to put a $1 label on and be done with it vs. spending time discussing it with an inspector or finding it mentioned in a home inspection when you are selling the place.

[Ne0eN]

How in-accessible?

Can you crawl over to it if you break out some sheetrock in the garage or something?
If so, that's what I'd do.

If it's see-able, but not crawl-able, maybe you can do EMT easier than fishing wires or fishing flexible metal conduit. You can potentially bend a 90 to go up through roof. Then because it's fairly rigid you can push the conduit out in front of you and into place and then up out through a hole.

OR you can run conduit on the roof for 4' so that it's at a point where you can drop through into an easier to handle space.

There is perhaps enough room to put my hand in. It's basically another roof section that joins the main roof on a different level. That part of the roof is right over my kitchen so there is no attic space under it. My kitchen has high cathedral ceiling, so I will try to remove one of the recessed lights, and see if there is some sort of path for conduit. I'm sure there is some insulation to deal with as well.

[foo1bar]

"My kitchen has high cathedral ceiling,"
I've seen cathedral ceilings with zero space between the roof and the ceiling (rafters are the ceiling joists - with insulation in the bays so no room at all.
And I've seen cathedral ceilings where there's ~3' between the ceiling and the roof.

Since you say there's room for your hand it could mean there's room to run a conduit below the rafters. or it could mean you're going to have to run it inside a rafter bay where there's also insulation.

There's a lot of potential options you have - you'll have to figure out what will work for your situation.