I am trying to get to the bottom of an issue that has now happened twice to a caravan manufacturer we sell Victron Inverters to.
The AC input cable has burned up, even though the system was not connected to site power, so there should have been no power on the AC input.
The AC input is wired from the inlet plug, through a 16A RCD to AC input 1 on a 12v 3000VA Multiplus. There is an oven and a fridge wired in parallel with the inverter, directly from the RCD.
The report from the recent customer was this occurred when the aircon was being used. The inverter was being run from the AC output of the inverter, from the batteries. Normally the Air con uses about 700W, but was drawing 1400W this time.
A local electrician was hired to change the AC input cable, and the problem persisted afterwards. I think this rules out the likelihood that a staple could have been put through the active and neutral on the input cable.