Long Term Use of Shore Power

[Rowana]

I have a "Zinc Guard" GI from Merlin Equipment fitted to Rowana.

To quote from the instruction sheet -
Note: EARTH BONDING IS ABSOLUTELY ESSENTIAL TO ENSURE CORRECT SAFETY. IT IS ILLEGAL AND DANGEROUS NOT TO BOND AC EARTH TO METAL PARTS AND DC NEGATIVE ON BOARD"

Give them a ring on 01202 697979. I found them most helpfull people to deal with.

 

[tillergirl]

This is all very helpful. TG is wood and built at a time that builders didn't do electrics other than basics. So on the 12v side everything goes to the battery -ve and engine block. The prop shaft is electrically isolated from the engine. I have a permanently installed battery charger and now have an immersion heater currently not wired in on the newly installed calorifier. So until now, 'shorepower' has just meant the battery charger being turned on. Shorepower has had no 'deliberate' earthing to the -ve side; I am assuming there is no normal connection between the earth of the battery charger and the negative to the batteries. So I was going to add an RCD/MCD from which I would run the battery charger and immersion and put a GI in series on the earth into the RCD. I wanted to omit any link between shorepower earth and -ve and anode. I lie to a swinging mooring so this 240 stuff only gets used during cruises.

 

[Nuvalec]

Back to the original question - yes you can use an rcd protected lead to your heater.

Just one question - whilst you're doing this, how are you charging your batteries? Shorepower?

BTW linking all the earths up on boats doesn't form a big battery. What it does do is build up a certain amount of voltage on the earth circuit into the water from all those people who DON'T have a galvanic isolator and ruin it for the rest of us.

Tony.