Solar install turning out really bad - looking for some help/advice please.

[foo1bar]

Well, it looks like we kind of have to do new permits. I called up SolarEdge and the inverter will not accept anything bigger than 6AWG wire. An adapter would need to be used, which isn't shown on the permit, so that wouldn't pass either.

Not a new permit - a change to the existing permit.
Probably for this one you can make the new plan, probably they'll want the changes in red (easily identified when reviewing).
And I'd probably put a note like:
"Change: Changing wire size from #2 to #6 for wire from inverter to main panel. Was mistake on original plans."

For a small change like that, possibly they won't even charge you.
(depends on the planning dept.)

Obviously you need to make sure that #6 is OK code-wise. I don't recall what exactly your setup is. If it's OK for amperage with whatever de-rating is appropriate for it's location, then that's the route I'd take.


Obviously asking the planning dept what they want in a plan-change submission and how much they charge should just take a quick phone call. (probably 30 min on hold and a 3 minute conversation)

[HX_Guy]

Not a new permit - a change to the existing permit.
Probably for this one you can make the new plan, probably they'll want the changes in red (easily identified when reviewing).
And I'd probably put a note like:
"Change: Changing wire size from #2 to #6 for wire from inverter to main panel. Was mistake on original plans."

For a small change like that, possibly they won't even charge you.
(depends on the planning dept.)

Obviously you need to make sure that #6 is OK code-wise. I don't recall what exactly your setup is. If it's OK for amperage with whatever de-rating is appropriate for it's location, then that's the route I'd take.


Obviously asking the planning dept what they want in a plan-change submission and how much they charge should just take a quick phone call. (probably 30 min on hold and a 3 minute conversation)

I asked the inspector and she specially said we would need a new plan submitted. I think too many changes for just a revision (new conduit fill calculation etc). Ill give them a call too though.

[foo1bar]

Yeah, probalby not the way I'd want to go. Easier to just get a couple new terminal blocks and replace the existing ones. I just need to see if I can remove those little DC+ and DC- plastic pieces and attach to the new terminal blocks so it looks "oem".

IMO filing a plan change is easier.

Is there any reason that #6 isn't OK? (ie. do you really need #2 or anything larger than #6? If not, fix the plans to be what they should have been in the first place.)

[HX_Guy]

IMO filing a plan change is easier.

Is there any reason that #6 isn't OK? (ie. do you really need #2 or anything larger than #6? If not, fix the plans to be what they should have been in the first place.)

Definitely do not need #2, that's way overkill (good for 115A @ 75º C). The inverter will never "request" more than 34.5A per SolarEdge, even with the NEC 125% rule, that's 43.13A. 6AWG wire is good to 65A @ 75ºC.

[SunEagle]

Definitely do not need #2, that's way overkill (good for 115A @ 75º C). The inverter will never "request" more than 34.5A per SolarEdge, even with the NEC 125% rule, that's 43.13A. 6AWG wire is good to 65A @ 75ºC.

I just thought about that 1" conduit from your combiner box to the attic. Will it be big enough to even run 2 x #2 AWG + ground + that red wire for your panel string?

If not, you need to change your plans concerning that #2 wire and reduce it to what is really needed. The #6 might work if it meets the voltage drop calculation.

[SunEagle]

Edit: Please do not clip the strands to make it fit in the undersized terminal block. Please.

I agree with you. NEVER clip any strands to make a wire fit into a terminal.

[HX_Guy]

I just thought about that 1" conduit from your combiner box to the attic. Will it be big enough to even run 2 x #2 AWG + ground + that red wire for your panel string?

If not, you need to change your plans concerning that #2 wire and reduce it to what is really needed. The #6 might work if it meets the voltage drop calculation.

According to the conduit fill calculator I used, it comes out to 31% conduit fill, which I believe is fine per NEC. Plus it's what the permit says.

[SunEagle]

According to the conduit fill calculator I used, it comes out to 31% conduit fill, which I believe is fine per NEC. Plus it's what the permit says.

OK. I wasn't sure of the wire size for the green ground wire & red DC wire. Just wanted to make sure you didn't have to replace that conduit in your attic.

[HX_Guy]

OK. I wasn't sure of the wire size for the green ground wire & red DC wire. Just wanted to make sure you didn't have to replace that conduit in your attic.

They are both #10 THWN-2 wire.

[Mb190e]

I have been watching this thread and the others from HX_Guy since the beginning. I'm a do it yourself kind of guy. I've built additions, all phases of construction, roofing, garages, sheds, hardwood flooring, installed complete kitchens, installed furnaces, wiring and plumbing for entire house, etc... After watching this story unfold, I will say hiring competent solar installer to do the solar install was the best $10,000 I ever spent. Hopefully HX_Guy can put this all behind him soon.

[SunEagle]

I have been watching this thread and the others from HX_Guy since the beginning. I'm a do it yourself kind of guy. I've built additions, all phases of construction, roofing, garages, sheds, hardwood flooring, installed complete kitchens, installed furnaces, wiring and plumbing for entire house, etc... After watching this story unfold, I will say hiring competent solar installer to do the solar install was the best $10,000 I ever spent. Hopefully HX_Guy can put this all behind him soon.

I agree with you. Sometimes it is worth spending your hard earned money on a proficient Contractor then saving a few bucks.

I also believe that HX_Guy has done an outstanding job fixing the issues left by his Installer and will end up with a class act solar installation.

[foo1bar]

Definitely do not need #2, that's way overkill (good for 115A @ 75º C). The inverter will never "request" more than 34.5A per SolarEdge, even with the NEC 125% rule, that's 43.13A. 6AWG wire is good to 65A @ 75ºC.

These wires are going into conduit that is on top of the roof?
I think they are - which means you have to derate the current capacity.
And how much you derate depends on temp - which depends on how far off roof surface the conduit is. And also what the design temp is for your location.

[HX_Guy]

These are actually thru the attic, not on the roof. Do they still need to be derated?

[Living Large]

I have been watching this thread and the others from HX_Guy since the beginning. I'm a do it yourself kind of guy. I've built additions, all phases of construction, roofing, garages, sheds, hardwood flooring, installed complete kitchens, installed furnaces, wiring and plumbing for entire house, etc... After watching this story unfold, I will say hiring competent solar installer to do the solar install was the best $10,000 I ever spent. Hopefully HX_Guy can put this all behind him soon.

I haven't installed a system yet, but everything else you said I agree with. Everyone could see this #2 vs #6 thing coming, since he mentioned the discrepancy. It's a darned shame. I hate to say this, I learned a lot though his problems. Hang in there, HX_Guy - you're almost there.

EDITWell, I did not do some of those things. Kitchen install and entire house plumbing. I'm glad I called a professional for my plumbing, because I had no clue about venting guidelines, test procedures, etc.

[SunEagle]

These wires are going into conduit that is on top of the roof?
I think they are - which means you have to derate the current capacity.
And how much you derate depends on temp - which depends on how far off roof surface the conduit is. And also what the design temp is for your location.

The conduit runs out the bottom of the combiner box, then down into the attic so shouldn't need to derate the wires.