I have seen other people asking similar questions but with no answer, so I try again here. Just finished installing my Multiplus in my camping car. While on "on" mode, the Multiplus 1200VA works fine as an inverter, it converts 12DC to 220V AC. But when switched to charger only mode, connected to a standard, grounded home plug, it refuses to take the 220v in. I can tell it tries to switch to the grid (I can here a click inside the multi), but immediately switches back to inverter mode. It's like it refuses the AC from the grid. I checked the tension and it is 224v. Any ideas ? Many thanks for your help.