no ground fault indication

[AdamEto]

On this new build yacht i work on there is not going to be any ground fault indicator installed, we have got a 400v 3 phase 4 wire system with neutral connected to ground. The explanations i got was that i dont need any indications beacause if i have any earth leak over 10 amps the breaker will trip and therfore no damage will be done,
But what if i have many small leakages less than 10 amps?
Won't this be bad for the yachts hull? Paint,Anodes
How can earth be connected with neutral together?
Thanks for the help.
Adam

 

[waross]

You do not need ground detectors or lights on a grounded system.
Don't connect to shore power. Even if you connect and measure no hull current, the next day, another vessel with a heavy load on the neutral may connect nearby and cause hull currents and severe corrosion on your vessel. The vessel causing the problem may remain unaffected. Such is the nature of hull currents with grounded neutral systems on shore power. Some vessels have a knife swith installed in the connection from the system neutral to the hull ground. The switch is opened whenever the vessel goes on shore power.

Bill
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"Why not the best?"
Jimmy Carter