Growatt SPF-3000TL LVM ES; buzz, pop and then goes dead?

[apctjb]

Recently installed 2 SPF-3000TL-LVM-ES 48. Tested after installation and inverter and MPPT charging all worked fine. (No grid hookup so did not test utility charging) They worked for about a week in MPPT charging mode (inverter side was not turned on as did not have loads attached). After a week I went to connect loads and powered on one of the two inverters (the 2 inverters were configured to operate in parallel (setting 23=PAL), there was buzzing noise, then error warning, then three load pops (no smoke) and one of the inverters when dead. No load was connected to either inverter at the time. No display, no response when powering on.

Looking at the data log there was an over current error prior to the inverter failure.

Anyone else experience a similar situation and any suggestions on how to troubleshoot/repair?

 

[timselectric]

Would have to know how you have them wired up to troubleshoot.

 

[apctjb]

Inverters connected to shared 560AH battery, 2 separate 3KW PV arrays, no grid input, AC output connected to 2 separate circuit breakers which were open at time of failure.

 

[timselectric]

I would double check the AC output wiring.
And all of the grounding.

 

[apctjb]

Finally had time to do a more throughout inspection. Found that one of the IGBT's on the main board had blown. These are rated 600V, 80A. Unlikely a voltage problem so suspect either a current issue or simply random component failure. The inverter was not connected to any loads at time of failure. Any thoughts on what caused the failure?

 

[timselectric]

Could have just been a timing issue.
It might have been slow to turn off. And was forced to carry all of the current for a split second.

 

[AntronX]

Any thoughts on what caused the failure?

Look for burned traces or other visibly burned components.