Bonding, etc.

[alanporter]

My 1976 Westerly Renown does not have the through-hulls bonded to any common earth point. Except, that is, for the engine cooling water intake which is bonded to the engine. My shore power system earth wire,(120 volt in Canada), is not connected to the DC common earth point, as is recommended by some people. I always check that the shore earth connection is good before using any 120 volt mains appliances.
My philosophy for all this is that the risk of galvanic corrosion will be reduced. Am I correct ? or should I be doing something else ? Expert advice will be much appreciated.

<hr width=100% size=1>Alan Porter

 

[DMGibson]

Best advice is NOT to connect the shore power earth to any underwater part on your boat. If you do, there is a chance that your boat's fittings will provide a better earth connection than the one on shore, and any earth leakage from appliances anywhere in the locality will be grounded through your boat. That will eat away your fittings quicker than anything.

Incidentally, the best protection from electric shock from mains electricity is an RCD (which used to be called an ELCB in the UK). The unit disconnects the supply if there is any imbalance between live and neutral, ie a current through a person holding the wrong bit! They should disconnect the current within 30milliseconds, which they tell us is enough to prevent injury to the unfortunate victim.

<hr width=100% size=1>