SMA troubles

[jma]

The installer was a no-show....called ahead and apologized, will be here Monday, oh well.
The system has been working, no errors, but generates a max of ~1700 w.

[oregon_phil]

Dang it.

In the mean time, you can go to YouTube and watch "Solar Panels - SMA Rapid Shutdown Problems [SOLVED]" to see how one user documented failure of the SMA RSS rapid shutdown box.

I am interested in the values selected in your parameters screen around the inverter and operation pull downs.

I also wonder if you have string learning turned on or off. If you can provide a snap shot of the parameters screen DC settings we could figure that out.

[jma]

The system has been working on and off, in the last couple of days when it gets first light in the AM goes into error 3401/2 for 60-90 minutes, errors then go away and starts producing power up to and above 7000 W. New tech was here yesterday, determined it was wired improperly and will come asap with help to go on the roof, expose the boxes and correct the problem.
Asap could mean at least a few days...he advised to shut the system down till repaired but wasn't totally against leaving it on as it seems to recover and generate power. It's on for now, I'll keep monitoring. I took a pic with cover off, don't know if it'll be of any help. In the past I think I stated 24 panels, but I was wrong; they are 26, 18 facing south and 8 facing west.

[oregon_phil]

First Photo: Did you notice one of the screw heads is already rusting? Your installer didn't use any duct seal on the conduit openings. My local energy trust also required dielectric grease on all exposed power connections like the DC and AC wires going into the inverter. Those plugs on the black Polaris block are suppose to keep moisture out, but mine didn't. My installer should have put some dielectric grease on those too.

Second photo: Input A and B are obviously in parallel mode. Did you notice the 510VDC value is higher than the SMA 7.7 inverter input range 480VDC (high value). While 510VDC is lower than the 600VDC max rating and lower than 550VDC max MPPT range, 510VDC does technically violate one of SMA's specs. That's why the inverter is throwing an error.

Input A and B are in bridge mode (Strings A and B are paralleled together). String C is by itself.

Questions:

1) I think string length is still a mystery.
2) How is each string wired to the SMA rapid shutdown RSS box and then into the inverter. I'm trying to figure out


String A and B 1680 watt each, 510 VDC, 3.29 amps
String C 1000 watts, 242 VCD, 4.14 amps

All of this seems very odd. What kind of wiring did the past installer use?

In one of my first posts on this thread, I said the SMA inverter will throw an arc fault if String A and B are properly paralleled on the roof at the SMA RSS rapid shutdown, but installed improperly on inverter inputs A and C or B and C. Your original issues were arc fault issues, now you have DC over voltage.

It would help if you would post the complete event log for the start up of your inverter from the past couple of days. If you had the event log from the original arc fault issues, that would be historically helpful too.

3) Also, I can't read the DC wire gauge inside the inverter. Do you have any better pictures?

[nerdralph]

3) Also, I can't read the DC wire gauge inside the inverter. Do you have any better pictures?

Looks like #10 RPVU to me.

[jma]

I'm not sure what kind of wiring the original installer used and I have no more pics at the moment unfortunately. I'm attaching a PDF event log, the first time I saw overvoltage was at the end of August. I can't seem to be able to go back to 2019 on the event log, sorry.
This has been frustrating but a learning experience at the same time. I hope the new installer can get here quickly.

[oregon_phil]

When you provide log files, can you provide the log file from the inverter not from sunny portal? The inverter log file also has error codes attached to each event.

#1 Thing for the installer to do: Trace each wire and draw a schematic from roof top solar panels to ac breaker panel.

Can you send a copy of your installer device parameter tab like you did for instantaneous values tab?

Here's a couple of things you can do while you are waiting for the installer.

Note date and time: push rapid shutdown button, Wait until Green LED lights up, reset rapid shutdown button

Wait 5 minutes

Copy inverter instantaneous value tab contents

Note date and time: turn OFF AC shutoff, turn OFF DC shutoff on inverter (left side of inverter, should show 0 on knob cutout area)

Wait 5 minutes

Note date and time: Turn ON DC shutoff on inverter (should show 1 on knob cutout area), turn ON AC shutoff

wait 10 minutes

Copy inverter instantaneous value tab contents

Send inverter instantaneous value tab contents (2), device parameter tab contents, and log file.

we want to see if the inverter thinks there is a fault during any of these operations.

Thanks!

[jma]

Finally, some results. Ryan, the local tech was able to diagnose and rectify my problems. He promised me a detailed description of what he did, but for now I'm just happy the system is working properly with no issues or error codes since yesterday at around 10 AM. He did say the wiring wasn't done the way it was supposed to; he lost me with some of the technical terms he used, but will send me details of before and after
The original installer who created all these problems with removal/reinstall for the new roof is pretty much MIA, numerous phone calls and emails have gone answered and of course they failed to correct the problem. Maybe I should pursue some legal way of holding them accountable, but this isn't the place to discuss it.
Again, my thanks to all who have helped, especially oregon_phil. I'm learning and will continue to learn thanks to this forum.

[oregon_phil]

Thanks for checking back in with us to close the loop. I am hopeful that your problems are solved with the new local tech. The inverter tries to update firmware and/or refresh network connections once a week. So let's make sure you get through this 7 day update/refresh period before claiming victory. The 7 day network refresh cycle can't be turned off and will happen even if you turn off firmware updates. I'm crossing my fingers for you.

[jma]

Thanks for checking back in with us to close the loop. I am hopeful that your problems are solved with the new local tech. The inverter tries to update firmware and/or refresh network connections once a week. So let's make sure you get through this 7 day update/refresh period before claiming victory. The 7 day network refresh cycle can't be turned off and will happen even if you turn off firmware updates. I'm crossing my fingers for you.

Right you are! Let's see what happens in the next few days. Today it worked fine, no overvoltage or errors of any kind. I'm still waiting on the detailed explanation from the local tech. I also am crossing my fingers.