electrolysis and earths on boats

[ericmark]

Has anyone been involved in wiring a boat and the electrolysis problems involved with importing an earth. I am considering an isolation transformer and not importing an earth at all. But although all items can run from a 3Kw transformer hysteresis losses when plugged in 24/7 are a concern and also overload problems where multi-items are required at the same time. Consideration has also been given to running a DC charging unit and an inverter along side the straight isolated supply so basically two isolation transformers with will increase the hysteresis effect when both units are on but allow either unit to be switched of on no or little load. I know with generators units are available which sense load and only turn on the generator when required is there similar for isolation transformers. Also on washing day for a few hours only what would be the result in connecting an earth and using direct power for limited time only.
Although I have been an electrician all my life I have never come across this problem before. The people using the boat are skilled an electrician and his wife a plumber so having a system needing user input is not a problem but also I can’t do anything which is dangerous both in eroding the hull or giving them shocks.
This must be regular problem and I will guess there is a standard way around the problem.
Eric

 

[Stoday]

Most of the hysteresis current to a transformer is magnetising current, which is not registered by a kWh meter. Check the kW loss of the transformer; it should be quite small.