Earth Ground vs Neutral

[M99]

With a 300 DA, should there be any connection between the Green Earth Ground System that is connected to all the sea water metal, and the Engine Ground / Neutral? I do have a Galvanic Blocker in the Earth Ground circuit. I know that with house wiring, we do have such a connection, but not sure with boats and I'm trying to chase down a grounding problem. Thanks.

 

[Westie]

The neutral wires are totally separate from the Engine ground (more correctly called the return or negative) and the ground bonding system except that the neutral is bonded to the ground bonding system at a single point. That single point is at the source. On the case of a boat the source can be a generator, shore power, an inverter or an isolation transformer. It must only be bonded at the active source. So if you are connected to shore power the generator bond or inverter bond must not be connected. When running off the generator it's bond is connected and all the others are left open.

 

[M99]

Thanks. That is what I thought and that is similar to a home system where we bond the Neutral and Ground together at the ground spike or water pipe. I think that explains the problem then. My starboard Engine does seem to have the connection to the Earth Ground, but my Port Engine seems to lose that connection when the Shore Power cable is disconnected, even if the shore power breaker is off. Of course the breaker only break the Hot side.