New system stuck on night mode and not producing

[Lina916]

The MC4 is a pretty standard item. As I understand the rigging, panels are connected with wires cut from bulk, onto which the MC4s are crimped. It's a weatherproof, positive locking connector that snaps together with a pronounced click and then requires a special tool to disconnect it. Our problem was one that hadn't been snapped together all the way.

So there might be one like that, or the crimping could be faulty. We talked to another contractor about troubleshooting our system when the installer was ignoring us, and a poorly crimped MC4 was the first thing they mentioned.

My further understanding is that the array is wired in series (so the voltage adds) with a termination at the end of the string, so panels on the inverter side of a bad connection won't partially produce because the system isn't sensing the termination. Maybe someone more knowledgeable can confirm or correct that understanding?

Andan thank you for the information. After looking at my blueprint and reading through the info you provided I understand what you are referring to. I might jump on the roof myself and give a look for any loose wires and the MC4. I did some research and have what I need to file a complaint. I also spoke to a claims advisor from the county court and know the process for small claims now.

[solarix]

FYI - all the connectors going to the PV panels are the "MC4" type. They have a little O-ring gasket on the mating surface that seals the connection and can make it hard to get them to click together. There are now many manufacturers making MC4 "equivalent" connectors, but they all vary slightly and you can get mismatches between the different brands. Your PV panels all use the same brand of course and we rarely have connection problems between panels. The first place to look for problems is on the home runs - where the PV panel connector mates with whatever brand connector is on the wire going down to the inverter. We use the trusted Amphenol (a leading connector maker) brand from DigiKey.com. The biggest online electronic supplier in the world. (Better than the high prices from your average solar distributor...)
With the inverter in "night" mode - you should see a consistently low voltage on the strings which should be traceable to the bad connection. Could be the array was just wired wrong with some of the panel's polarity backwards. Seen that a few times....

[oregon_phil]

oregon_phil thank you for replying to my solar panel issue. To answer your questions:

I believe my system has never worked. The reason I think this is because I have researched two years worth of PGE statements and NetGen is '000000'. I ordered third year to see if they generated when they were initially installed.

Solar Edge SE3800H-US with display panel (night mode is lit up)
Trina Solar Panels -All Max Plus
15 panels
Blueprint:
Array 1
[x5] (N) Modules

Array 2
[x6] (N) Modules

Array 3
[x4] (N) Modules

Thank you kindly for offering to help. I tried to reset the inverter again today. I click the red switch to 0. Turn the knob to OFF then turn off at breaker box. I do see the panel lose power. When I work backwards to bring it back up I see the green light come on and the Night Mode displays. Highlands Energy said they will get back to next week. I actually got a hold of the installer but he no longer works for the company. Right away he said it must be paperwork that was not completed on PGE end. He said he'll call me tomorrow. Until then I'm all ears for suggestions and troubleshooting. I may jump on the roof this weekend to check for loose wiring.

Maybe knowledgeable SolarEdge inverter people can respond. My thoughts after reading the SolarEdge Document "Application Note - SolarEdge String Sizing, North America".

For single phase residential inverters with one optimizer per panel:

Minimum string length: 8 (6 with P405/P505)
Maximum string length: 25

And there are a bunch of other specs too.

In order for your system to work, all of the arrays must be wired in series. In other words, the blueprint should show a wire going from the inverter, to Array 1, from Array 1 to Array 2, from Array 2 to Array 3, and from Array 3 back to the inverter. If the solar panels are not wired in series, then the system does not meet spec.

Also, be very careful when you are up on the roof checking your connections. Even though the power optimizers are supposed to throttle panel voltage to 1 VDC unless properly connected to the SE inverter, if the panels are improperly wired and optimizers are not connected by mistake, high voltage can be found on the PV wires even if the inverter is off. The SE inverter document clearly states this fact in the inverter manual and is part of the commissioning process (PV voltage should be 1 VDC times the number of panels, anything higher could be an panel that was wired directly to the string).

If your are comfortable with electricity, an easier first step would be to turn off the inverter, turn off the AC, open up the inverter, check to see how many strings are attached to the DC inputs (you should have one), then measure the DC voltage across the + and - terminals with a digital volt meter (it should measure approximately 15 VDC).

[Lina916]

Hello, I wanted to update the forum about my solar panels. Highlands Energy replaced the inverter via warranty with a brand new one. Everything works and I am able to verify the panels are producing by using the SET APP from Solar Edge. Thank you to everyone that chimed in and offered advice for getting this issue resolved.