We are operating a sailboat with a Victron Multiplus 24v 3000Va charger/inverter onboard. We have recently been hauled out of the water for work and we now have some strange things going on. While we are on inverter power everything appears to be ok. When we plug in and switch the shore power on (3 pole switch/breaker) then we have 75vac between hot and ground, and 48vac between neutral and ground. There is 48vac between the grounded components of the boat and the dirt. This is happening regardless of if the multi-plus is active or not (when on shore power and the incoming 3-pole switch is closed). There are no shorts between hot & ground or neutral and ground on the plug side of the shore power switch. There are also no shorts between hot and ground on the boat side. This was determined by turning everything off and testing with a multimeter. This is perplexing and I am thinking that the multi-plus has failed or that there is a problem with the shore power. However the shore power tests just fine as well with no shorts and voltage only between hot and neutral, and hot and ground. Currently the chassis of the Multiplus is not tied to the ship's ground I will be working on that today, it is bonded however through the ac input line. We have an ELCI after the multi-plus which does not trip. The Multi-plus is wired directly inline from the switch for shore power, and is wired directly to the ELCI, which then goes back to the distribution busses.
Update: grounding the chassis of the multi-plus to the ship's ground has not resolved the issue.
Thank you.
