My Solaredge system dead. How to figure if it's an optimizer or inverter that's bad?

[sensij]

The AC Disconnect is on the roof. Right next to the inverter. If there was a bad connection likely it was the one in the breaker box that I got. But, theoretically it could be the AC disconnect, too, right? Or also the spring-loaded AC out connectors in the inverter, though unlikely.

Either way, the installer has created a ticket with SolarEdge, who says it is a monitoring issue only (ha!). So we will see how long all this takes to resolve, because it sure as heck is not just a monitoring issue; that I can prove with certainty. But, I've got to step back and let the installer and SolarEdge work through it their own way on their time.

Yes, the disconnect is another opportunity for a bad termination.

With a rooftop mounted inverter (which is really unconventional), have you looked at any of the temperature data to see if it is overheating? That is another reason the system could be mis-behaving.

Re-pairing the optimizers is something you can do yourself without opening anything up, but you do need direct access to the inverter.

[kny]

on the roof should be all DC.

The AC Disconnect is on the roof. Right next to the inverter. If there was a bad connection likely it was the one in the breaker box that I got. But, theoretically it could be the AC disconnect, too, right? Or also the spring-loaded AC out connectors in the inverter, though unlikely.

Either way, the installer has created a ticket with SolarEdge, who says it is a monitoring issue only (ha!). So we will see how long all this takes to resolve, because it sure as heck is not just a monitoring issue; that I can prove with certainty. But, I've got to step back and let the installer and SolarEdge work through it their own way on their time.

[sensij]

on the roof should be all DC.
SolarEdge uses spring loaded connections which are generally better than torqued connections but that all assumes they are used correctly which is certainly questionable with an installer willing to use undersized cable and breakers.

Yeah, even spring loaded connectors can be done wrong, especially with stranded wire. I like spring connectors, but try hard to use ferrules on all of the stranded conductors. The twin connectors are a legit way to double tap a termination otherwise rated to accept only a single wire.

[ButchDeal]

So, I just opened up the breaker box and pulled the breaker for the solar. I don't know how you quantitatively measure quality of connection, but one of the two hot legs appeared mostly disengaged with only maybe 1/8" connecting. I loosened, jammed in fully, and tightened. Certainly seems like it was a poor connection. Next I'll check the connections at the ac disconnect and in the inverter, but it's raining now, so not going up on roof.

on the roof should be all DC.
SolarEdge uses spring loaded connections which are generally better than torqued connections but that all assumes they are used correctly which is certainly questionable with an installer willing to use undersized cable and breakers.

[kny]

The inverters data log is too slow, and even the display probably doesn't respond fast enough to catch the AC voltage spike. You need professional equipment to diagnose this, but a loose connection would be enough to cause the symptoms you've seen.

So, I just opened up the breaker box and pulled the breaker for the solar. I don't know how you quantitatively measure quality of connection, but one of the two hot legs appeared mostly disengaged with only maybe 1/8" connecting. I loosened, jammed in fully, and tightened. Certainly seems like it was a poor connection. Next I'll check the connections at the ac disconnect and in the inverter, but it's raining now, so not going up on roof.

[kny]

Thanks everyone for all the informative responses. This has been educational and informative. I have lots to discuss with my installer.

[adoublee]

Not only this this an NEC issue for wire size, but SolarEdge documentation says recommended breaker or fuse size is 35A or 40A on a 240V system.

[ButchDeal]

Yes, I know how ethernet over powerline works. My point is that the optimizer the inverters states is unreporting is still reporting data out.

They do not use ethernet over powerline or IP at all. They do communicate over the DC power line but not via IP. You should re-pair them to the inverter or the installer should.

Wire probably is too small. I'll ask installer how they determined 10 AWG was ok. But, 6000/245 = 24.5 amp and assuming the SE-6000 inverter never puts out more than it's max output of 6kw, this amperage should never be exceeded, so 10 AWG over 60' is borderline bad but not egregious. An SE7600 would clearly need bigger wire with 32 amp max output.

Max continuous output current for the SE6000A is 25 amp so a 30a breaker is too small. (25 X 1.25% = 31.25) If they could find one they could have used a 32a breaker (unlikely) or a 35a breaker (also unlikely)

I'm not happy about the ungrounded optimizers and I'm not happy the AWG is at best pushing the envelope or at worst simply too small. Nonetheless, I am 98% certain my issue is a bad inverter. I just went through a full reboot cycle and all 22 optimizers came up as P_OK. It is a cloudy day, so production would be small. Yet, within 60 seconds the AC VOLTAGE TOO HIGH error came up and during that minute the VAC was 245 and the VDC was in the 440s, far higher than the normal 370 the system always ran at under all conditions.

The Inverter will have the optimizers produce higher DC voltage as needed for higher AC voltage or to produce less power etc.

So, if all optimizers are reporting, something is causing the inverter to drive the system at an exceptionally high 440 volts and then shut down for high AC volts (though the screen never went above 245).

Weird stuff (zero production periods in middle of day) was happening back on 4/11 and 4/12 and then seems to have been simply up and died.

My installer has finally responded. So, hopefully I'll get some movement on this.

It was still a poor install back then as well.

[sensij]

Yes, 30amp breaker. It has never tripped.

No, it wouldn't trip. The problem is that at full output, you exceed 80% of the breakers rating. That is not allowed by code.

The inverters data log is too slow, and even the display probably doesn't respond fast enough to catch the AC voltage spike. You need professional equipment to diagnose this, but a loose connection would be enough to cause the symptoms you've seen.

The high DC voltage is expected when the inverter stops producing power. Re-pairing the optimizers is important when not all are reporting correctly and voltage is not falling to a safe level automatically... That fixed a similar problem on my inverter.

[kny]

90 deg terminals don't exist in this application. 60 or 75 deg for any consumer or commercial equipment. 10 awg is not code compliant for this inverter. Hopefully the installer at least used only a 30 breaker with it, at least then the conductor is protected, and the violation shifts toward having an undersized breaker for the supply.

Yes, 30amp breaker. It has never tripped.

[kny]

it is still too small of a wire.

The optimizers do not report via IP. they send their data to the inverter and the inverter sends the data to the cloud.

Yes, I know how ethernet over powerline works. My point is that the optimizer the inverters states is unreporting is still reporting data out.

Wire probably is too small. I'll ask installer how they determined 10 AWG was ok. But, 6000/245 = 24.5 amp and assuming the SE-6000 inverter never puts out more than it's max output of 6kw, this amperage should never be exceeded, so 10 AWG over 60' is borderline bad but not egregious. An SE7600 would clearly need bigger wire with 32 amp max output.

I'm not happy about the ungrounded optimizers and I'm not happy the AWG is at best pushing the envelope or at worst simply too small. Nonetheless, I am 98% certain my issue is a bad inverter. I just went through a full reboot cycle and all 22 optimizers came up as P_OK. It is a cloudy day, so production would be small. Yet, within 60 seconds the AC VOLTAGE TOO HIGH error came up and during that minute the VAC was 245 and the VDC was in the 440s, far higher than the normal 370 the system always ran at under all conditions.

So, if all optimizers are reporting, something is causing the inverter to drive the system at an exceptionally high 440 volts and then shut down for high AC volts (though the screen never went above 245).

Weird stuff (zero production periods in middle of day) was happening back on 4/11 and 4/12 and then seems to have been simply up and died.

My installer has finally responded. So, hopefully I'll get some movement on this.

[sensij]

I suppose, the number of micro inverters remaining on line could be viewed as a way to handle excessive AC
line voltage.

I don't think any private level grid tie inverter has provision to lower output to limit AC line voltage. Since every
installation has a different impedance and voltage situation, a one-fits-all solution might be difficult. Maybe the
mfrs could be convinced to come up with a gradual power reduction vs AC voltage, but that could cost a lot of
production if trip out isn't likely. Remember, this isn't even supposed to happen. Bruce Roe

There is no reason to take individual panels off line in an mppt system. The mppt is capable of moving off of the maximum power point to limit power output. This functionality already exists as "clipping", and can be set to any arbitrary power output maximum withing the inverters rating. When a Solaredge system is provided data from a revenue grade meter, it can do more advanced power management like zero backfeed into the grid, if desired.

[sensij]

... which #10 wire cannot be used unless every terminal and conduit is 90C rated.

90 deg terminals don't exist in this application. 60 or 75 deg for any consumer or commercial equipment. 10 awg is not code compliant for this inverter. Hopefully the installer at least used only a 30 breaker with it, at least then the conductor is protected, and the violation shifts toward having an undersized breaker for the supply.

[sensij]

I think Butch mentioned it in an earlier post, but re-pairing the optimizers should be an early step in the troubleshooting when not all are reporting.

I'm using 8 awg for a 40 ft run on a 7600 W inverter, almost went with 6 awg. 10 is too small.

[ButchDeal]

Thanks. Wire length is closer to 50 feet than the 100 feet I stated previously. ~2 foot run from inverter to AC disconnect and then about 50' run to back-fed breaker at main panel. More direct route than I thought.

I have identified the power optimizer that the inverter reports as "Non-reporting". This optimizer, however, does show in the monitoring portal with data and recent "last measurement" timestamp. So, it is alive and at least reporting data via ip, but the inverter does not see it.

it is still too small of a wire.

The optimizers do not report via IP. they send their data to the inverter and the inverter sends the data to the cloud.