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

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  • Originally posted by SunEagle View Post
    Makes sense keeping the inverter out of the hot sun. Yours should be ok on the North side.
    Yeah, I figured better outside than inside the garage where I measured ambient temperature of 126º over the summer (garage door faces west)...and it wasn't even that hot this summer!

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    • Finally getting somewhere with the city. Called and spoke with someone who said I could stop by to pick up a copy of the approved permit (up till now I was going off an older version of the permit, not the official one). The lady also put me in contact with the Building Official who said they would setup a courtesy inspection even though it's not something they normally do. He was a bit skeptical at first, probably thinking I'm just complaining about some cosmetic issues but once I told him about different gauge wire than what's specified in the permit, he was all ears. Funny thing is the permit packet actually has a spec sheet for the correct type wires, so the installer knows what's needed to do it right, he just isn't doing it.

      About the roofing, he confirmed that the inspector does not go up on the roof and it's practically impossible to verify for flashing. He did say that the standoffs need to be installed as recommended by the manufacturer, which technically the Unirac hanger bolts were, but they also have to match the permit plan, which they don't since that shows aluminum standoffs. He said he actually just had an employee at the city go through this, they bought a house that had solar and did a home inspection, the inspector found there was no flashing installed and the home seller had to pay a few thousand out of pocket to redo the install before the buyer went forward with the purchase.

      Now that I have the actual permit, I think I can contact him with exactly what is wrong and what needs to be fixed. I took a quick look outside and so far found:

      "No DWV, MECH or B-Vent penetrations allowed under solar panels" - He put railing to mount panels right over vents
      " #4 AWG THWN-2 wire" - He used #6
      " #4 AWG THWN-2 wire" - He used #8
      " #10 AWG USE-2 wire" He used #10 THWN
      " 1" EMT" - He used 3/4" nonmetallic LiquidTight
      " 1" EMT" - He used 3/4" EMT

      Maybe some of this stuff is ok and I'm being too anal? I don't even know anymore.

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      • It's really kind of scary the shortcuts being taken. 99.9% of homeowners wouldn't have a clue even what to look for and I guess these contractors know it.

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        • Originally posted by Ian S View Post
          It's really kind of scary the shortcuts being taken. 99.9% of homeowners wouldn't have a clue even what to look for and I guess these contractors know it.
          It really is crazy. And forget the aesthetics of it all, it's really a fire safety thing that I'm truly concerned about. Maybe #6 AWG will do in place of #4 but using #8 instead of it? Half the size, in a plastic non-fire rated tube...on the side of the house where all the electrical and gas meter is?

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          • Is this the installer you are using?

            substandard.png

            The wire size might be safe as far as current rating, but might have excessive voltage drop for the length. You could figure it out yourself for a fun exercise, if you want. Remember it's a round-trip (50 feet run = 100 feet for loss calculation).

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            • Yeah I might look into it, it's really not a very long run. From the combiner box to the inverter it's approx. 25 ft. The permit calls for 2AWG wire there, which now I notice on the inverter spec sheet that it will only allow a 6-14AWG wire for the DC input connector...soooo not sure on that one.

              Then between the inverter to the disconnect its about 10 ft and the permit shows 4AWG wire there and again from the disconnect to the service panel it's maybe 3-4 ft.

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              • Originally posted by HX_Guy View Post
                Yeah I might look into it, it's really not a very long run. From the combiner box to the inverter it's approx. 25 ft. The permit calls for 2AWG wire there, which now I notice on the inverter spec sheet that it will only allow a 6-14AWG wire for the DC input connector...soooo not sure on that one.

                Then between the inverter to the disconnect its about 10 ft and the permit shows 4AWG wire there and again from the disconnect to the service panel it's maybe 3-4 ft.
                Quick follow up, I punched in a few numbers here and I came up with 14AWG per string?

                http://rimstar.org/renewnrg/solar_vo...ing_for_dc.htm

                507.36V with a 5% loss at 9A for 25 feet (50 feet gives the same result).

                But since the strings are being combined in the combiner box, then I need to multiple the amps by 4 (for 4 strings), correct? So that then gives me 10AWG. Does that sound right?


                And then from the inverter to the service panel, I have 240V @ 5% loss with a max. continuous output current of 47.5A for 10 ft which gives me 8AWG. Now I know for derating the panel, they use a 1.25% multiplier so 47.5A is really 60A, which is what the breaker is. That then gives 6AWG.


                EDIT: Called SolarEdge and they calculated that if the run is less than 30 ft from the combiner box to the inverter, then an 8AWG wire would be fine or 6AWG if I really want to have some extra capacity.

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                • Originally posted by HX_Guy View Post
                  Quick follow up, I punched in a few numbers here and I came up with 14AWG per string?

                  http://rimstar.org/renewnrg/solar_vo...ing_for_dc.htm

                  507.36V with a 5% loss at 9A for 25 feet (50 feet gives the same result).

                  But since the strings are being combined in the combiner box, then I need to multiple the amps by 4 (for 4 strings), correct? So that then gives me 10AWG. Does that sound right?


                  And then from the inverter to the service panel, I have 240V @ 5% loss with a max. continuous output current of 47.5A for 10 ft which gives me 8AWG. Now I know for derating the panel, they use a 1.25% multiplier so 47.5A is really 60A, which is what the breaker is. That then gives 6AWG.


                  EDIT: Called SolarEdge and they calculated that if the run is less than 30 ft from the combiner box to the inverter, then an 8AWG wire would be fine or 6AWG if I really want to have some extra capacity.
                  I'm not following all that, but for such short lengths, there is no way you should have
                  to take a 5% wire loss. Are you sure it doesn't INCLUDE the inverter loss, since 25'
                  or 50' are the same? My total AC & DC wire loss is a bit under 5%, with panels located
                  as much as 700' away from the meter. And no 2 gauge here. Bruce Roe

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                  • It didn't seem to make a difference if I used 2% or 5% and honestly I didn't know which to use. Either way it does seem that 2AWG and even 4AWG is way overkill, not sure why it was speced that way in the permit. The installer's 8AWG seems fine here, though when the city inspects it, it wouldn't pass and it would have to be changed to match the permit or the permit amended. I was just at Home Depot though and wire is pretty cheap, probably less than $100 for all the wiring we need from the combiner box all the way to the service panel.

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                    • Originally posted by HX_Guy View Post
                      It didn't seem to make a difference if I used 2% or 5% and honestly I didn't know which to use. Either way it does seem that 2AWG and even 4AWG is way overkill, not sure why it was speced that way in the permit. The installer's 8AWG seems fine here, though when the city inspects it, it wouldn't pass and it would have to be changed to match the permit or the permit amended. I was just at Home Depot though and wire is pretty cheap, probably less than $100 for all the wiring we need from the combiner box all the way to the service panel.
                      Do you really think they inspect the wire size from the front seat of their vehicle when they are signing off on the instillation ?

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                      • My inspector made the installer disassemble the breaker box, and he checked ALL the wiring. Even the non solar related stuff.

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                        • My inspector looked at the wire sizes at the main and sub panels, so my inspector wouldn't have passed wrong sizes. Same with a friend of mine in a different city. I would therefore assume that the wire sizes may be inspected and need to be correct.

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                          • I'm just wondering now how we get a 2AWG wire into a hole made for 6AWG wire. I'm thinking the inspector isn't going to disassemble the inverter to see what kind of wire is between the combiner box (which will be on the roof) and the inverter. The other wires though, in the meter and disconnect though are very easily viewable without having to undo anything really.

                            On a positive note, my 40 panels and 102 Quick Mounts are being delivered tomorrow. But on a negative note, I haven't heard from my installer since Tuesday. Sent him a text yesterday morning, no answer. Tried again this afternoon, no answer.

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                            • Originally posted by HX_Guy View Post
                              I haven't heard from my installer since Tuesday. Sent him a text yesterday morning, no answer. Tried again this afternoon, no answer.
                              NO>>>NO>>>>NO>>>

                              Dont call, dont text, dont do ANYTHING!!

                              You want to kick his ass off the job, and you can do so as "Abandonment".

                              If you would have taken my advice and contacted a construction lawyer.... you would already know this.


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                              • And who is going to pay or have time for this construction lawyer? I don't want to drag this out to court and other things, I just want my system finished and producing electricity.

                                Honestly my ideal situation would be for me to finish up the project like I said earlier...do the roofing, do the wiring and then have him put up the panels since I can't handle that part and whatever else he needs to be part of for the commissioning/inspection, plus he holds the permit and I don't want to start that process over. I don't need it warrantied by him or any other of his services.

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