Reverse Polarity

[sel1005]

First off, let me say that I am NOT an electrician, have zero expertise in that area. Having said that, I need your help.....

Boat has been on the lift for a few months now, connected to shore power, all was well....

Went down today to check things and my helm fan (plugged into helm outlet) was not running. Did some tests and here is what I found:

1. shore power shows on and available on the control panel; 110-120V tester on the dock plugs show fine; I don't have a 240V tester however, so can't test the shore cord going to the boat
2. either on Shore 1 or 2, the control panel breaker is off; if I try to reset, it flashes reverse polarity and immediately flips back off

where do I go from here?

A. thinking I should try a different shore power cord to the boat?
B. buy a 240V tester and try the dock power plug?
C. lower the boat in the water and see if things will run on the generator, try to isolate it to the shore power?
D.???

Other than what the GW boat manual suggests, "have an qualified electrician check things out", what else would you recommend I try?

Thanks much for your help!

 

[seasick]

How did you test the 120 at the dock? Did you use a voltmeter or did you use a tester that checks polarity, grounding, neutral etc.?

Are you connecting 220 to the boat or dual 120s. If the former, the 220 outlet could be wired incorrectly even if the 120s are correct. It is tought to diagnose from here. I don't know if the dock service is 3 phase or single phase. There may also be an issue on the vessel. If you are unfamiliar with electric work, especially marine electric, I kind of agree that a pro should look at it.

 

[sel1005]

I used a plug in tester for the 120 outlets that are connected to the same breaker box. The type that lights up if there are any problems. Don't have a 220 tester for that circuit. The electrical has been in place for 6 years, as has the single shore power cord. No changes, and until a day or two ago, has never had an issue. Its the same on both connections to my boat, Shore 1 and Shore 2. Never heard of a shore power cord going bad, but guess that could happen too?

 

[seasick]

I used a plug in tester for the 120 outlets that are connected to the same breaker box. The type that lights up if there are any problems. Don't have a 220 tester for that circuit. The electrical has been in place for 6 years, as has the single shore power cord. No changes, and until a day or two ago, has never had an issue. Its the same on both connections to my boat, Shore 1 and Shore 2. Never heard of a shore power cord going bad, but guess that could happen too?

I would switch off all breakers and then only switch on the mains and see if you get the reverse polarity indication. If not, then switch on breakers one at a time until the 'alarm' occurs. That may isolate a problem with a specific piece of equipment

 

[sel1005]

Exactly what I did today. I used a spare cord just to be sure nothing was wrong there, and then did as you suggested. I'm thinking now it may be a bad 220V circuit breaker, but will test that tomorrow after church.

I could hold power on both Shore circuits, and interestingly enough, I could flip any of the ones on Shore 2 and keep power, but any of the circuits on Shore 1, which is the main one, would automatically flash the reverse indicator and flip off. Gave me the idea to test the 120V which had tested OK before, and any load at all on that one flipped the breaker on the dock off at the box.

So the good news is the boat seems to be OK, but the dock power comes on but will not take any load on either 120V or 220V circuits.

I'm going to replace the master breaker on the dock, but if that doesn't work, I'll have to get an electrician to look for ground faults or shorts I guess. This is a dedicated line, so nothing else draws on it.

If you have any other things to look at or test, please advise, I really appreciate your help.

 

[seasick]

Exactly what I did today. I used a spare cord just to be sure nothing was wrong there, and then did as you suggested. I'm thinking now it may be a bad 220V circuit breaker, but will test that tomorrow after church.

I could hold power on both Shore circuits, and interestingly enough, I could flip any of the ones on Shore 2 and keep power, but any of the circuits on Shore 1, which is the main one, would automatically flash the reverse indicator and flip off. Gave me the idea to test the 120V which had tested OK before, and any load at all on that one flipped the breaker on the dock off at the box.

So the good news is the boat seems to be OK, but the dock power comes on but will not take any load on either 120V or 220V circuits.

I'm going to replace the master breaker on the dock, but if that doesn't work, I'll have to get an electrician to look for ground faults or shorts I guess. This is a dedicated line, so nothing else draws on it.

If you have any other things to look at or test, please advise, I really appreciate your help.

You are probably on the right path. You might also check to see if bugs, nests or other junk has collected in the electrical boxes. That can cause stray current paths but you are probably looking at a bad breaker ( that would be the simplest issue and I hope that is what you have)

 

[sel1005]

finally got it resolved, called an electrician. He used a pretty cool tool, a ground fault tester(?) and walked around the yard until he pinpointed the spot where he thought something was going on. When we dug up the spot and found the 4 lines, he just pulled the lines with his finger and one of them popped apart. Spliced the line back together and secured it and everything works fine again. It was right next to one of my sprinkler heads, so also glad I did not get in there and work on that sprinkler! Thanks for your help and ideas.

 

[seasick]

finally got it resolved, called an electrician. He used a pretty cool tool, a ground fault tester(?) and walked around the yard until he pinpointed the spot where he thought something was going on. When we dug up the spot and found the 4 lines, he just pulled the lines with his finger and one of them popped apart. Spliced the line back together and secured it and everything works fine again. It was right next to one of my sprinkler heads, so also glad I did not get in there and work on that sprinkler! Thanks for your help and ideas.

That's great.
Thanks for the update