Electrical mystery-reverse polarity’

General
1

When I plug the shore power cord into the Honda generator, the AC power panel reads reverse polarity. When I plug the boat into the shore power plug, it does not. Current is fed through the boat to the batteries exactly the same. The generator was serviced this winter and the draw was tested and it received a clean bill of health. This started happening midway through last season.

2

So if I understand you are saying

With the Same Generator/Boat /Power cord/Marina Power distribution outlet.

This error began mid season prior to servicing the Honda.

I believe the Honda has what is known as a floating ground

(there is no continuity to the true ground)

I would check on what that might be expected to do.

I would purchase one of those cheap 3 prong, 3 light polarity checkers.

I would use that to check

The marinas out put

The generators output

An outlet in the boat in each case

AND

The 120vac/12vdc inverter’s out let if you have one

I have no idea what could be wrong if everything is correct

Fran

PS I just got this from AI

**
AI Summary**

To understand how a floating ground effect reverses polarity indicators, consider these points:

  • A floating ground is not directly connected to the earth, creating an unstable reference point.
  • This instability can cause voltage levels to fluctuate unexpectedly.
  • Reversed polarity indicators rely on consistent voltage direction to function correctly.
  • When the ground floats, it can lead to incorrect voltage readings at the indicator.
  • The indicator may show reversed polarity due to the altered reference point.
  • Proper grounding is essential to ensure accurate polarity indication and system safety.
3

Is the Honda genny an integral part of the boat or an ungrounded portable that is so common on our boats?

4

I should have clarified that I use a portable Honda 2000.

5

You can make or buy a neutral bonding plug for your generator which bonds the neutral and ground. This makes battery management systems “see” a ground when operating off of a generator including reverse polarity sensors. This is a common practice among RVers using portable generators who have a BMS.

6

Thank you Ed. I will try that. I found one on Amazon. The mystery is, why it only started happening years after I’ve been using the generator the same way.