question

This happened again this morning at 04:26. Batteries had finished charging some time before and pull from the grid was 500W

However the grid did not fail. Just AC Out dropped for some seconds but long enough to make all my devices reset and wake me up.

This morning with SoC >95% from the overnight charge running from batteries I opened the breakers to the AC_in to check. Everything continued to work as I expect. No complaints from anything and eventually a grid lost alarm.

This is exactly as I expect so the loss of AC-Out randomly is an internal error with one or both of the MP2s in my opinion.

There are no logs as I understand on the MP2 itself and the Cerbo just reports the disconnection of input and VE.Bus off. The input never disconnects.

Thinking about it, it seems to only have happened since I had to swap out to two newer MP2's under warranty late December. Prior to that (and although only 2 months in service) I never had this issue.

One thing I do have since swapping them out is when I unplug the VE.Bus from the Cerbo I get a low battery alarm on the MP2's. Is this related and this error is causing the internal running to falsely shut down then start up? Sound logical to me but if so how to fix or check?

Never had that with the older two (in their short, but longer than these new ones, in-service period) and nothing changed. Same config files used.

Can anyone help on this or suggest where to look for the cause?

Thanks

Happened again this morning at 04:20!

Upgraded to v501 reprogrammed and reset the Cerbo to default. All rather inconvenient but all nice and clean.

Let's see what that does as nobody else seems to have any input ;(

I have a similar issue, but I'm getting overload warnings (both on grid and off grid) yet my wattage doesn't go above 7000w on any 1 phase.

I can't figure out what's going on, so pushing this to my supplier.

With the warning does it shut off briefly?

I might have to log it out to my supplier too as I had it happen again this morning around 09:30 which was obviously really annoying after all I did yesterday.

I made a CT clamp change early Jan and I reverted that this morning just in case it is that. I don't think it is related as this issue is the AC_out. But who knows. It is not a grid loss and happens so fast my UPS doesn't trigger an alarm to my server yet trips in the house and my alarm complains.

There were a few things done late December - like add 2 more batteries (of which one of the newer ones was moved to the master), an inverter swap and I shortened the VE.Bus cables (with factory ones again). Could be any of those things, or none.

I can only make one change at a time to find it :(

Photos of my pair of inverters.

The photo with 2 x VE.Bus cables is the one replaced early December. Problems started a few weeks afterwards...

The other photo is the one in service since pretty much day one.

Can you spot the likely source of my random issue?

20230129_191500.jpg

20230129_191506.jpg

Nobody?

I had THREE more outages in quick succession this morning at 07:45 before I had a chance to rectify the issue below.

I gently touched/brushed the bridge cable and the lights went out! I moved my finger away and they came back on. I hoped and expected this would happen as obviously a loose connection, due to no attempt to screw that in on the assembly line, would trigger a remote off/on.

No way did this shake loose in transit.

If this is the source of my issue (which is highly likely and hopeful) a lack of QA here @Victron has caused a lot of inconvenience and head scratching (for me).

If you get random shutdowns with VE.Bus state "off" in the logs, check the switch and this remote on/off terminal.

@mvader (Victron Energy) perhaps something to check in the QA - a simple missed screw terminal making the MP2 unstable. This one was an RMA replacement HQ2234.

Thanks.

Thank you. I've checked my two new MP2. The left screw was loose on both units but not as bad as shown in your picture. But the right screws were tight.