Hi, Everyone.
I am currently the user of a 3 Muliplus II inverters 10000/48V in 3-phase configuration and ESS and in combination with a Fronius Symo 10KVA and 12 Pylontech 3500C.
The system has been running correctly without any issues since September 2023.
Yesterday morning I was surprised to see that the power at my house disappeared without any reason which was strange since I was relying on my backup system.
I checked the system on the VRM portal and I noticed that around 8.28 am there were 2 alarms, one for the High DC ripple and one for the Low Battery Warning which actually shutted down my system. After a few minutes the system came back in operation again and again after around 17 minutes it was down again for about 2 and a half minutes and again after 17 min down and so on.
My batteries were charged about 66%.
I have not touched the system since September 2023 since it has been running just fine. I checked for cables looseness and everything seems to be just fine
The low battery issue only happens on the last inverter which is for phase 3
All 3.inverters have the same DC input value for the batteries the same cable length for DC and AC
I suspect that the invertor is damaged or there is something wrong with the battery pack, or the BMS.
I switched the inverters off and they have been off since yesterday. I checked the VRM portal a few minutes ago and there is still an alarm for the High DC ripple.
Do you have any ideas of how to fix this!
Thanks in advance
First you need to establish if there is something that needs to be fixed.
Start with the bank.
Are all of them physically ok?
With the inverters (and mppts etc) disconnected or off, does the bank switch on and report correctly to the GX?
Do the inverters power up no load or ac input without errors? Led or otherwise on the GX?
If they do fine after , then proceed to load test them (best done as stand alone units) . If you can replicate the issue, then there is a problem.
If they do fine, proceed with a firmware update on all components and re program etc. then recommission.
Or if they don’t do well you can proceed to do a full pre rma test, found here.
Otherwise i can tell you we have had this happen exactly once also with a Pylontec bank. (Zero explanation as to why - many theories -we think and since it never happened again- there was a problem with the incoming AC and phase angle, that caused an absolute wobble). Entire system is stil working and this was 2 years ago
PS this wont clear until you restart the system.
Hi
Thanks for your fast reply.
The batteries bank seems to be in order.
No errors, no messages.
The inverters are off now and even with no load the behaviour is always the same. 17 minutes the system works just fine and then it goes off for about 2.5 minutes and so on. It all started suddenly.
I attached 2 snapshots.
If you have tested then you know the answer.
Have you opened it up and had a look? It could possibly be a problem with the power pack - the capacitors may have visible bulging.
It probably needs to be removed and returned for an RMA.
But do the due diligence first.