Flash and bang

[Zap-pow]

I’ve been running a single Growatt 5k for 3 years. 3-eg4 batteries. Decided to parallel another 5k. After settings changed and all paralleled, had a big flash out of inverter #1. Tried to start individually. After master booted up, started 2nd unit. This time bang outta #1. Start #2 alone and it gets 51 error with no load connected. I think both are toast.

 

[jorby]

That is extremely troubling to hear. Obviously they were not syncing properly. On my inverter (EG4) if I change the main operation mode, it requires a reboot to install the new mode. So I would have to set each inverter to be the master or slave, with a reboot of each, BEFORE connecting them together. I might try to find the manual for yours and see what it required, just out of curiosity.

 

[jorby]

sniped from spf-5000 manual (others probably similar) Notice step1 (all breakers on outputs off in case of potential problems)

 

[LydMekk]

Been there, they did that to me too.
4 of them.
Growatt crap.

 

[jorby]

and this is the mode selection stating that the inverters need to be in standby to change to parallel (similar to mine) then reboot to install the new operating mode. (with the output breakers still off). I see no way to damage either unit if those breakers were off and they are the last thing to be turned on after verifying that there are no errors. Unfortunately, breakers only protect the wiring, not the semiconductors in the inverter. The error 51 on #2 is over current. Disconnect #1 completely from #2 (all wires and cables). Set #2 to single and see if it will start up. It might not be dead if no bang/flash came from it.

 

[jorby]

Further inspection of their wiring diagram reveals that they do not show output breakers for each unit. They show only one breaker with both units connected to it. So if you wired it like their diagram, the outputs are not isolated from each other and then this COULD happened if anything went wrong during the restart. Disgusting.

 

[Zap-pow]

and this is the mode selection stating that the inverters need to be in standby to change to parallel (similar to mine) then reboot to install the new operating mode. (with the output breakers still off). I see no way to damage either unit if those breakers were off and they are the last thing to be turned on after verifying that there are no errors. Unfortunately, breakers only protect the wiring, not the semiconductors in the inverter. The error 51 on #2 is over current. Disconnect #1 completely from #2 (all wires and cables). Set #2 to single and see if it will start up. It might not be dead if no bang/flash came from it.


View attachment 262859

I disconnected #1 and got #2 inline again as a single unit. I followed procedure on the startup so not sure what happened. Inverter #1 is out of warranty so I’m screwed. But I sure as hell don’t trust #2 to buy another one and blow it up.
I guess I could get them online w/o load and check to see if they are phased by metering outputs. Should have 0V L1 to L1 and/or L2 to L2.

 

[Zap-pow]

Been there, they did that to me too.
4 of them.
Growatt crap.

Man that’s sucks. I may go to a single large inverter. I could ditch the transformer too.
Signature Solar informed me one of the inverters is out of warranty. I’ve had both inverters back to warranty for various issues and it just keeps getting worse at every turn

 

[Hedges]

Would it still be out of warranty if the clock stopped each time it failed, didn't restart until repaired, returned, back in use?

You could also pressure them that a unit repaired repeatedly under warranty was never good, request replacement. Even with a used one (considering they've had some trade-in programs, might have something in stock that isn't much book value.)

 

[jorby]

I disconnected #1 and got #2 inline again as a single unit. I followed procedure on the startup so not sure what happened. Inverter #1 is out of warranty so I’m screwed. But I sure as hell don’t trust #2 to buy another one and blow it up.
I guess I could get them online w/o load and check to see if they are phased by metering outputs. Should have 0V L1 to L1 and/or L2 to L2.

So #2 is still alive?

Yes, checking phasing with the outputs disconnected is what is implied in the instructions when they said to have the output line breakers to the units turned off. The inverters would have done that check and showed an error if there was a problem. It would not have blown if those breakers were there and open. BUT they do not show the mentioned isolation breakers in the wiring diagram so how are you supposed to do it correctly the first time? From what I could tell in the manual there are no breakers in the inverters for that purpose. True? Then I would complain that the instructions (wiring diagram) were wrong, leading to this disaster. The one being out of warranty is irrelevant. It failed by random chance. Would they have covered it it the 2nd one was the one to pop instead?

 

[Zap-pow]

So #2 is still alive?

Yes, checking phasing with the outputs disconnected is what is implied in the instructions when they said to have the output line breakers to the units turned off. The inverters would have done that check and showed an error if there was a problem. It would not have blown if those breakers were there and open. BUT they do not show the mentioned isolation breakers in the wiring diagram so how are you supposed to do it correctly the first time? From what I could tell in the manual there are no breakers in the inverters for that purpose. True? Then I would complain that the instructions (wiring diagram) were wrong, leading to this disaster. The one being out of warranty is irrelevant. It failed by random chance. Would they have covered it it the 2nd one was the one to pop instead?

I’m still in an email conversation with them. They seem to be slow rolling me. Not responding for a couple days at a time.

 

[Zapper77]

I’ve been running a single Growatt 5k for 3 years. 3-eg4 batteries. Decided to parallel another 5k. After settings changed and all paralleled, had a big flash out of inverter #1. Tried to start individually. After master booted up, started 2nd unit. This time bang outta #1. Start #2 alone and it gets 51 error with no load connected. I think both are toast.

Crossed L1 and L2?

 

[Zapper77]

I disconnected #1 and got #2 inline again as a single unit. I followed procedure on the startup so not sure what happened. Inverter #1 is out of warranty so I’m screwed. But I sure as hell don’t trust #2 to buy another one and blow it up.
I guess I could get them online w/o load and check to see if they are phased by metering outputs. Should have 0V L1 to L1 and/or L2 to L2.

What did you use for a load side combiner? Polaris or breaker panel?

 

[Zap-pow]

Crossed L1 and L2?

No. I checked and rechecked wiring. I sent Signature a video of myself going over the wiring by hand. The tech also said my input, output grounds shouldn’t be tied together but they are tied inside inverter so that didn’t make sense.
He also said my N from my transformer shouldn’t go to house panel but to the generator switch I’m using. But my understanding is there should only be one N tie and that’s at the main panel.

 

[SignatureSolarJess]

Hi! I'm so sorry you're still having trouble! If you'd like to reach out to me in a DM with your contact info, I'd like to see about getting this escalated for a resolution!

 

[Zap-pow]

What did you use for a load side combiner? Polaris or breaker panel?

I wire nutted parallel AC lines and used a buss bar for the DC

 

[Zapper77]

I wire nutted parallel AC lines and used a buss bar for the DC

How did you provide OCP?

 

[robbob2112]

A picture would be worth a thousand words... showing how the wiring is connected...

 

[Daddy Tanuki]

I do not know anything about these particular units, but my magnums as I found out need all wiring completed, parallel communication cables in place and then powered up at the same time. the inverters talk to each other, decide on and sync the frequency and then both turn on. powering them up separately leads to protections kicking in as they are not sync'd frequency wise. just a thought.

 

[Zap-pow]

How did you provide OCP?

Breaker

 

[Zap-pow]

sniped from spf-5000 manual (others probably similar) Notice step1 (all breakers on outputs off in case of potential problems)

View attachment 262858

There is no N on inverters. L1 and L2 and G.

 

[jorby]

There is no N on inverters. L1 and L2 and G.

I read it again and see what you mean. I realize that the instructions I found were not necessarily for your exact unit. European versions often have one labeled line and the other labeled neutral. An american version would be labeled like yours, because neither is at the same potential as our "neutral" which is actually at 120v from either terminal. The two versions are probably the same inside except for possibly a neutral/ground bonding screw in the euro one.