Inverter / Charger Backfeed

[mgmh 58]

Hello knowledgeable boaters.
I experienced the following problem on my recently acquired sailboat & I am puzzled how it could have happened.
I have a Freedom 20 (120V) charger/inverter for my deep cycle batteries. The charger is also hooked up to a 240V to 110v step down transformer. Whilst attempting to charge my batteries with a Honda EU 20i (240v/8.33 amps) generator my inverter/charger experienced a " backfeed" & shut down. I have not been able to reset the unit, so I will be removing the charger with a view to having it repaired, assuming it is a sensible option.
What puzzles me is that a few weeks ago the system worked well when plugged into shore power at the Marina for almost five days. I live in Australia, hence the 240v power supply & the need for a step down transformer. To clarify matters the AC power goes to the transformer first & then to the inverter/charger. Has anyone experienced this or a similar problem?
Thanks.

[tuberider]

i assume that you have a selector switch for the gen. and the shore power.it might have to do with the switching of both 240v legs. make sure the switch disconnects both leads from the sources. are you using the load side of the inverter for anything. 240v boat with 120v inverter. if you do have something hooked up to 120v make sure the neutral is not connected to the rest of the boat. it has to be isolated.

[mgmh 58]

Hi tuberider,

Thanks for the suggestions. I am not sure if there is a separate switch on the Honda. Will check it out this weekend. The hot water heater is hooked up to 110V & I am quite sure it is isolated from the rest of the boat.

Kind regards
Michael