Hello, I just installed a new multiplus-11 12v 2x120 on my motorhome to replace my Magnum. I also have a cerbo with display screen. no solar hooked in yet. original agm batters still in. I connected the output to my circuit breaker panel and tested the unit and the invverter works fine. Ran my microwave and fridge. I then hooked up my shore power feed to the multiplus input and the trouble began. When I turn on the 50 amp breaker it trips instantly. I also get an error on my cerbo panel that says error code 24: Switch-over system protection initiated. yesterday for some odd reason one time it did not blow the breaker and ran perfectly all night. this morning I disconected shore power and tried to reconnect and it has tripped it a dozen times.
I have not really programed the multiplus since the mk3 was backordered.
some general troubleshooting:
1. Verified my wiring from shore power is correct. i even connected my surge protector and lights indicated the 50 amp recepticle is correct also.
2. bypassed my onboard ATS that switches between gen and shore. no effect
note: with shore power off i was annoyed by the beeping error and flipped the inverter switch off and on. so when I reconnected my ATS to the INPUT of the multiplus I got zapped and noticed AC on L1 and L2 on the inverter input while inverting.
3 tried switching off multiplus, even remoing battery terminals. still blows breaker
4. removed L2 of the input and oddly the inverter worked passing ac to my breaker panel and charging. but I am losing half my amps from L2
5. removed only L1 on the input and works also.
I do not know where to go from here.
