Multiplus unexepectedly inverting with grid power present

[ntimmerman]

Hi all,

One of our backup power systems using a multiplus inverter is given us problems.
It suddenly seems to lose grid power and then decides to start inverting. However, grid power is present at that time, so it shouldn’t start inverting. The interesting fact is that it always happens around midnight, see screenshot:

In the Alarm log, I also see many messages about Grid lost: however, it doesn’t tell me the reason.

Another installation at the same location shows the same behavior, although not always exactly at the same time. So we are thinking about maybe a grid frequency issue, however, when I look at the grid frequency for phase 1, I don’t see a correlation:

Should we try disabling LOM?
Or update firmware?

The Multiplus runs on firmware version v490, so it’s pretty far behind.

[nickdb (Nick)]

If you connect with a mk3, on the grid tab select NS log. It should list the last few causes of grid loss/rejection.
You can get this with dbus commands as well, just easier with the mk3.

Before fiddling with LOM, I would check that.
Would update the FW as well, there were some fixes in old versions but off the top of my head, can’t recall if it was addressed by 4.90.