After a day of sailing and returning to my slip at a local marina, the polarity alarm sounded after connecting shore power and switching my A/C panel on. I have had no problems with this in the four months of owning the boat nor have i had problems at the current marina. I have checked my outlets which have tested to be in normal working order and all the fuses are in good shape. The connection on the boat is dry and free of corrosion and the shore power cable is practically brand new.Any ideas?
polarity alarm
- Thread starter I.R. WC
- Start date
- Status
check the marina polarity
first thing I would do is check the potential between ground and neutral at the shore power plug on the dock
first thing I would do is check the potential between ground and neutral at the shore power plug on the dock
Polarity alarms (or breakers) are usually set up to detect too large a differance in voltage between neutral and ground. In a properly set up power supply the ground and neutral are connected togther at the marina's distribution panel and should never be more than a few volts differant at your boat. If you have a sudden onset of reverse polarity alarms then possible causes are that the ground connection has gone bad, or the neutral has a poor connection (leading to high voltage drop in it) or somehow you or another user is causing a high current flow in the ground wire. In any event take it seriously, possible outcomes are shock to yourself, fire, death of anyone in the water nearby, or massive and rapid corrosion (BIG bucks). In my opinion, if you are uncertain of what you are doing, purchasing an hour of an electricians time might be a good investment, there may be a combination of problems. Having seen what leaking electrical currents did to the outdrive on a friend's power boat in two weeks I unhook my power any time I am not using it. I also never swim in a marina. John Brecher
- Status