Recently installed a MultiPlus II 2x120, 24V on a boat that has both shore power and a generator. When connected to shore power or to generator, the unit works (inverts), but Cerbo Touch Display shows a ‘#8 Ground relay test failed’ error.
When disconnected from shore (and generator not running), unit will not invert and goes into fault mode (and shows #8 error).
I have pored through the troubleshooting guide VE.Bus Error Codes [Victron Energy], to no avail.
In the course of extensive troubleshooting, wire tracing, etc., we ended up completely disconnecting all AC lines. So no AC ‘in’, no AC ‘out’. Completely physically disconnected the AC lines. Only DC battery power connected. The MP still throws the same #8 Ground relay test failed error.
The error shows the relay is ‘open’ when it should be ‘closed’ (Error: PE2 Open). This seems to correlate with why it works on shore or gen (because the relay should be open in those situations) and does not invert when on battery (when the relay should be closed).
This seems to me to indicate a hardware (relay) failure inside the MultiPlus. Does anyone have any other ideas of what to look at? I'm already planning to start a warranty return tomorrow, but.. thought I'd check here also.
