Main Panel Reversed Polarity Light

[Fred Koehlmann]

So Dolphina was put onto the hard this last week and I'm up doing the obligatory winterizing of the pumping, etc. When I arrived last night the fist thing I did was search out the nearest power outlet (at the lamp stands and 120v 15 amp). When I hooked everything up and went to the panel and flipped the switch, the reversed polarity light came on (its still on). Since everything was fine in our slip for the season, I had no concern about what was on the boat, but assumed that the marina had their power messed up. Today I went to Canadian Tire and bought a nice Gardner Bender GFCI Outlet Tester. I tested the marina's outlet and it was correct! So now I'm worried, so I climb on board and test my outlets, they all say that they are OK as well. So now I don't know what to think. Is my main AC switch pooched? If so, why are the downstream outlets OK? 

FYI: My ProNautic 1240P charger is running OK with what its getting and I see that it also has a Reversed Polarity light, but it is NOT on, so it would suggest that everything is also OK. Or does that just mean that the DC is not reversed?  I'm sure the manual is somewhere.

[Jim Hardesty]

I'm not an electrical engineer or electrician.  When I've had problem with the reversed polarity light cleaning the shore power plug and/or extension cord contact prongs solved the problem.  I think it's caused by a poor neutral connection.
Jim

[Stu Jackson]

Fred, this may help, click the link in that, too.

http://c34.org/bbs/index.php/topic,3761.msg21053.html#msg21053

Get the definition of RP straight and you'll see why long extension cords sometimes do that.

[Fred Koehlmann]

Thanks Jim, the connections are themselves pretty good. I get the results with a new cord as well.

Thanks Stu, I read those articles before I posted. Since I left my tester at home, I went a got a new GFCI one, but as I mentioned it shows that all outlets downstream from the panel are OK, even the GFI outlet. You mentioned the length of the power cord. Is this something to do with loss of amperage or something over the distance (100 ft cord)? Or is it possibly because it is only a 15 AMP outlet that I'm drawing from? I'm trying to figure out if this is a false positive and don't need to worry, or if my main's reversed polarity wiring is broken, or if I really have something that I need to worry about. The tester is suggesting "no".

[Stu Jackson]

Or is it possibly because it is only a 15 AMP outlet that I'm drawing from? I'm trying to figure out if this is a false positive and don't need to worry, or if my main's reversed polarity wiring is broken, or if I really have something that I need to worry about. The tester is suggesting "no".

That's the conclusion I would draw.