I have a MuliPlus II 5kVA 48V which I installed to mitigate regular load shedding. The system has been idle for about 6 months after which it has had a trial by fire of about 20 events in the course of 2 weeks. It handled everything great except for on 2 occasions where the MultiPlus tripped and reported an overload as the grid failed. In both cases the load was minimal at the time of the trip +- 200W. In both cases I reset the system and reconnected the exact same load and the system came up fine.
Can anyone explain how this can happen? Is it possible for the grid itself to cause something that is reported as overload condition?
A portion of the cable run that feeds the Multiplus power from the grid shares a conduit with the cables that return power to the house. Could this be an issue (ie an induced eddy current)?