Can I Have an AC Neutral to AC Ground Tie “Jumper” on My Boat?

Question:

My marina just updated really old 15A shore power to new standards with GFI. Many boat owners, including my 1980 Carver 30 were unable to connect without tripping breakers. The marina advised that the problem was likely a common neutral/ground, on board. I checked continuity between the neutral and ground posts at the shore power plug to confirm. Yep, now I need to find the problem. I decided to start at the AC distribution panel and removed each individual neutral from the bus bar, checking to see which AC appliance might be causing the problem. No luck. I dug deeper into the box to see an OEM installed jumper connecting the neutral and ground bus bars. Apparently in 1980 that’s how it was done. Right? I removed the jumper and resolved the problem. However, also connected to that lug on the other side of the breaker was a reverse polarity warning light. Did I disable that warning system by removing that jumper? Thanks for your help. Btw, your YouTube videos are world class. - Steve

Answer:

Thanks for the feedback on the videos, much appreciated. You definitely CANNOT have a AC neutral to AC ground tie “jumper” on your boat. Good on you for catching this and removing it. The AC Reverse Polarity light is pretty straightforward, on one side it’s connected to your AC neutral, on the other side it is connected to your AC Ground. Since both the AC Neutral and AC Ground should be same voltage, the AC light isn’t normally illuminated. - Jeff