Reverse Polarity Indicator

[mattttt25]

2013 Grady-White 335 Freedom. Single 30-amp shore power outlet. No issues with shore power until 2 weeks ago. Found main 120V breaker tripped and reverse polarity indicator lit. Shore power source (dock) has been tested and appears to be fine. Shore power cable has been triple checked, including a brand new cable. So problem appears to be on the boat. Most often when connected and energized, the reverse polarity indicator immediate comes on. Sometimes, it isn't lit, but does when the main breaker is energized and then trips. A few times I could energize the panel, but it would show 60-70 volts.

I'm unsure what could suddenly happen to cause this. Everything on the DC side continues to work with no issues. Any suggestions on where to start troubleshooting? I looked at the outlet on the boat. No corrosion on the prongs. The outlet itself is completely sealed and protected. I guess I could start there and replace the outlet, but looking for guidance. Thanks-

 

[wspitler]

If you are certain that the shore power is not reversed then the problem is likely within the boats AC reverse polarity circuit. The low voltage you experienced is strange, making me think that the reverse polarity circuit was trying to cut the voltage, but couldn't for some reason. That is relatively rare in my experience. It is easy to check the shore side with a cheap tester from the hardware store. Although it shouldn't be a cause, I'd check the condition and reset the galvanic isolator as well. I'm not familiar with the location of the AC/DC panel in your boat, but if it is similar to my 330, all of the circuitry is on the back of the panel. Check that out for loose connections and corrosion, all power off of course. These type issues with GW mostly seem to be shore side related.

 

[seasick]

If possible, try to get access to another temporary slip with working shore power. Connect and see what happens.
Your panel could be shot. Have you had lightning storms recently?
If you are up to it, you can pull the panel out a bit and look for any indications of burnt or fried components. Disconnect shore power first though