Hello, this morning when I turned on the water heater, the boat immediately lost 220V power.  When one depresses the 220V panel water heater, two things happen at the same time:

1.  The RCD device at the dock kills power to all 4 boats that use the same column.

2.  The RCD device we installed in the engine room for all incoming shore power also triggers at the same time.

None of the above happens when power is re-enabled and consumers are turned on, except if one again turns on the water heater.

No actual breakers inside nor outside the boat are triggered.  For example, the dock-side 10A breaker does not trigger.  Only the RCD device protecting all 4 breakers for all 4 boats.

What do you think?  Thanks in advance,

Peregrinus

SM2K No. 350 (2002)

Compagnia della Vela, Venice