OK I'm a little stumped at this, I've had no problem for 6 months and there have been no changes except the recent addition of Home Assistance which only polls some Modbus TCP values. I can't really see that being the cause.
So there is a 50A MCB feeding a Small consumer unit via 10mm2 Armored in the CU a 50A MCB feeds AC-IN on a Multiplus II 10K (limited to 50A). There is also an EV charger connected to the same CU on a 32A RCBO.
Randomly both upstream and local 50A MCB's have almost tripped once a day for the last week. I have checked and there is hardly any load at the time (2 - 3 AMPs). This is in contrast to 00:30 to 04:30 every night when there is an ESS Scheduled charge and the EV charges. Both have dynamic load limiting which works perfectly. I see the load sitting at 50A for hours every night.
Normally I might think faulty MCB but I can't see 2 MCB's failing at the same time, and I'm sure a faulty MCB would manifest when fully loaded not at a couple of amps.
One strange thing I noticed, I happened to have the HA screen and Cerbo GX screen in sight when it tripped. The load info etc on the HA screen showed unavailable, which meant the HA Server lost communication with the Cerbo, and then I saw the Cerbo Screen reboot. This is odd as the Cerbo is powered from the battery not from the AC side so should not be affected by Grid Loss.
MCB's only trips on over-current there was no sign of that, not only did 1 but 2 MCB's tripped. Is there any logs or anything I can look at for more info or any suggestion as to the cause?
