question

A bit more info on your setup would be helpful...

It looks like you have 2 or more Multis in parallel, 1 master and 1 or more slaves. The VE.Bus error 17 can happen when the master is turned off in a parallel system and the VE.Bus error 3 when a slave is turned off.

It could be a problem with the comms between the units rather than the units themselves switching off.

The VE.Bus error 2 seems to indicate the two multis are not the same hardware level.

DC ripple happens when charging batteries from an AC source - the DC output will pulse or ripple as the AC voltage rises and falls. I've had this error when charging at too high a current or through battery cables that are too thin.

The overload could be because one of the paralleled units has gone offline.

If you could describe the hardware you have and what was happening at the time (load/ charge wise) it would help to diagnose.

Thanks for the reply, the first 2 times I tried to upload this post it failed, The third time I just typed the bare minimum to get the post up.

The system is 2 x Multiplus II 5000 connected to 12 Pylontech us2000s, Battery connected in pairs to a bus bar, and then each multi is connected using 70mm2 cable to the bus bar.

Solar is from a SolarEdge 6kW inverter

System has been fine for 6 months, the first 2 error times no one was home, but the last error last night happened around the time that charging from the grid would have started

Thanks

Lee

Is there any chance that any of the cat5 cables on the VE.Bus system could have been pulled or damaged in any way? Comms issues between components could cause these sorts of errors.

The 1st two errors yesterday were at a time of day where your solar input would have been at a maximum and (assuming you're in the UK) yesterday was the sunniest day we've had in a while. And then the error last night when the mains charging started, both times when the DC current to the batteries would have been at it's highest, so I'd also check all DC connections, circuit breakers etc.