I accidently connected the vacuum cleaner (approx. 1800W) to one of the sockets connected to my MultiPlus 500 while shore power was connected. It made a strong buzzing noise as from a relay switching really fast. The inverter works as usual but, now I noticed that the MultiPlus will not charge the battery and are not able to switch over to shore power as before when connected.
Did I burn the “push true” relay or is there any fuses on the 230V level?