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

[sensij]

The voltage on a simple string will be high when no current is being drawn. But the output of the individual optimzers should be only 1V DC when they are not in communication with the inverter.
And when the inverter is in control, I would not necessarily expect it to let the string voltage rise that high just because it is not willing to produce an AC output.

The DC voltage is allowed to rise to well above operating levels during the startup cycle / grid qualification stage. I've seen my inverter hang at that high DC voltage with no output when there was an abnormal shutdown that eventually required re-pairing the optimizers before successfully restarting. Although the optimizers return to 1 V as expected when the inverter is disconnected from the grid or they are asked to shut down by flipping the inverter's toggle switch, there seems to be at least one point in the state diagram in which they are allowed to run high.

After a quick look through my data, I can see another state in which DC voltage is allowed to rise is when the inverter goes into clipping, which may also explain some of what the OP observed in the first post in this thread.

[sensij]

One more observation... The Curb (installed at the service panel) was showing clipping at 5900 W. Clipping is confirmed by the high DC voltage at that time. If it is accurate, AC transmission loss could be found by comparing that number to what the inverter says it was putting out. For example, if the inverter was clipping at 6000 W, that is 1.7% transmission loss.

Until someone tries to determine if the AC spikes are real or just imagined by the inverter, I don't see the OP's situation getting better any time soon.

[kny]

I have just replaced the wiring from the inverter to ac disconnect to service panel and upgraded from 10AWG to 8AWG. Breaker also upgraded from 30 amp to 40 amp.

No change in behavior. Inverter goes through 5 minute waking up period, starts finding optimizers, mini screen reads 243 AC Volts, 410 DC Volts, hovers around 10-15 AC Power, goes click-click-click-click and then poof - AC VOLTAGE TOO HIGH

[sensij]

The click click is the last thing that happens before power is released (relays actuating, I guess). AC too high immediately would mean the power getting released has no where to go (running into high impedance), if all systems are healthy.

Do you own a volt meter?

Is the Curb fast enough that if you moved it to the inverter, it could measure voltage at those terminals instead of the service panel?

[kny]

The click click is the last thing that happens before power is released (relays actuating, I guess). AC too high immediately would mean the power getting released has no where to go (running into high impedance), if all systems are healthy.

Do you own a volt meter?

Is the Curb fast enough that if you moved it to the inverter, it could measure voltage at those terminals instead of the service panel?

The Curb ain't moving. I do own a multimeter.

[sensij]

The 10-15 W ac power on the screen *before* the clicks seems like a bad sign. I think I've only ever seen *0* until after the clicking is done.

[kny]

I'm out the door not to return until Monday, so further assessment must wait until then.

Keep in mind, however, two separate wire runs - one 10 AWG, one 8AWG - from inverter to panel make no difference. Next door neighbor has solar and is operating fine, so highly unlikely a grid voltage issue.

Hard to fathom it being anything but a problem internal to the inverter.

[sensij]

Hard to fathom it being anything but a problem internal to the inverter.

Yeah, I'm not saying it isn't the inverter, just trying to offer suggestions on how to rule out everything else.

I totally agree that trying to replace parts in the inverter is ridiculous, they should swap in a new one and repair the other at their convenience.

[Six4KilowWatt]

You should be under warranty. So with a few months you ought to have a warrantied replacement Look on the bright side, There isn't a helluva lot you can do. Once the new board works or doesn't work. A new inverter should be issued.

Too bad you didn't just go with micro inverters...None of this would have happened, and if you lost one, your whole system wouldn't be down.

[sensij]

Too bad you didn't just go with micro inverters...None of this would have happened, and if you lost one, your whole system wouldn't be down.

You can read more about the system planning in this thread:

https://www.solarpaneltalk.com/forum...hadow-elements

If there were any micro-inverters available that were compatible with those panels, maybe it would have been an option, but there weren't (and still aren't, as far as I know).

[ButchDeal]

Too bad you didn't just go with micro inverters...None of this would have happened, and if you lost one, your whole system wouldn't be down.

This is less then helpful. Had the installer installed micro inverters as poorly as they installed the SolarEdge system, it likely would be in the exact same situation.
Further as Sensij pointed out, micros really were not an option.

[SunEagle]

IMO is sounds more like a design and installation issue as opposed to a hardware issue. Even the best hardware can be destroyed by a poor installation and wiring.

[kny]

Decided to postpone weekend trip departure a few hours and install a new SE-7600 I bought because I cannot handle these endless delays and downtime. I'm already down a full month, easily over 1 MWh, which in the DC SREC market is $450 + $100 for electricity = $550 lost so far with no end in sight.

Anyway, with new inverter and problems solved. System putting out 6kw as we speak.

Off on vacation! Time to make up for lost time and start banking kwhs; my meter almost got back to 000000.

[ButchDeal]

Decided to postpone weekend trip departure a few hours and install a new SE-7600 I bought because I cannot handle these endless delays and downtime. I'm already down a full month, easily over 1 MWh, which in the DC SREC market is $450 + $100 for electricity = $550 lost so far with no end in sight.

Anyway, with new inverter and problems solved. System putting out 6kw as we speak.

Off on vacation! Time to make up for lost time and start banking kwhs; my meter almost got back to 000000.

so you got the upgrade as well.

[kny]

so you got the upgrade as well.

Well, I paid for it out of pocket instead of waiting endlessly for a comm board and then endlessly more for a replacement inverter. I've lost all leverage to be reimbursed by doing so, but don't care. Between delays by SolarEdge to get replacement equipment and delays by my negligent installer to do anything with it, it could easily be 2018 or legal action before my system was back up otherwise.

In summary, I now have:

• SE-7600 inverter
• P400 optimizers
• 8 AWG wire and 40 amp breaker
• properly grounded equipment
• clean wire management

It was a painful lesson to learn, but it was educational. And with the 7600 inverter I can add about 4 panels at some point in the future. Current strings are 13+9; roof can fit 16+10.

Thanks to all; this has been a very helpful forum.