Reversed Polarity Help

[Dwk]

When using AC shore power via a Honda 2000 the reversed polarity light blinks ONLY when I turn on the battery charger, no other AC appliances cause the polarity light to come on. Would a defective charger cause this? What/where should I be looking for cause and remedy.

 

[diver dave]

The Honda likely has no neutral to ground bond in place. So, you have a "floating" ac system off ground, confusing a primitive reverse polarity detect system.
Besides the light blinking, any other issue? I don't see this as a problem, so far.

 

[Dwk]

No other issues with operation of AC powered items ie,water heater, oven, refrigerator, and coffee pot. I often used the Honda and never seen this polarity light come on ,that's what is confusing

 

[DavidM]

I agree with diver dave's diagnosis above. Honda and most portable generators do not connect the grounding wire at the generator end. But if you disassemble the outlet you can get to the green wire coming from the load and connect it to generator's metal block. This will form a properly grounded circuit and should correct the reverse polarity light you are getting.


But I also agree with d d that it isn't causing any problem.


Davi

 

[diver dave]

As far as why the charger causes the light to blink. That is because many/most electronic items have some capacitors from L and Neutral to earth, usually as a RFI mitigation strategy. These caps will now allow small ground currents to flow. I suspect your polarity lamp is a low current LED type?
If you wanted to get further into this, take an AC voltmeter, and measure L to GND, and then N to GND, with/without the charger connected to see yourself how the line is "floating". Floating, means not tied to any reference, so is "non-deterministic".

btw, Navy ships have historically been floating, with an array of light bulbs in a panel for viewing by the electrician. The status of 3 lights (for three phase), indicates if any phase has a fault to earth/hull. Three dim is good. One out and two bright indicates a ground fault. This system is a very primitive ground fault indicator; not for human safety, but for ships fault tolerance.

 

[Dwk]

Thanks for the responses. We were anchored last evening and decided to get a slip today due to the excessive temps and humidity. When I plugged into marinas 30 amp service all was good, no reversed polarity light when charger was operating, I'm assuming its "floating" ac system off ground, confusing a primitive reverse polarity detect system.as Diver D stated and djmarchand concured. Thanks for the help.

 

[tiltrider1]

You should not use a portable generator on a boat unless you know for certain that the neutral and ground are bonded at the generator.

Many portable generators have isolated neutral and grounds. Yes, everything seems to be working fine until one day some one swims up to your boat and dies from Elextro-shock drowning.

 

[diver dave]

I think u will find that the live water shock scenario will require two wiring faults in either bonded or non-bonded cases.

 

[Comodave]

You should not use a portable generator on a boat unless you know for certain that the neutral and ground are bonded at the generator.

Many portable generators have isolated neutral and grounds. Yes, everything seems to be working fine until one day some one swims up to your boat and dies from Elextro-shock drowning.

+1.

 

[STB]

You should not use a portable generator on a boat unless you know for certain that the neutral and ground are bonded at the generator.

Many portable generators have isolated neutral and grounds. Yes, everything seems to be working fine until one day some one swims up to your boat and dies from Elextro-shock drowning.

I'm not seeing how a voltage differential can exist across the water with neither the generator's hot nor neutral interacting with the water.

With a single fault, we might connect the generator's neutral to the water. Or, we might get a hot wire in the water. But, we don't have a complete circuit.

But, I think we'd need two faults to get the hot in the water in one place, and the neutral in the water in another place, and the resulting voltage differential in between. This, for example, would require neutral and ground bonded on the boat and to metal thru-hulls and a hot wire in the water, or maybe an outlet getting swamped or a wet swimmer or something ending up with a human connected to both the hot and the neutral.

I'm not arguing that the safety ground shouldn't be bonded to neutral when on generator power. I'm just not sure on this particular scenario.

 

[Comodave]

It may not be a problem but I would hate to find out by someone dying from ESD.

 

[STB]

Comodave,

True that!

 

[tiltrider1]

It’s the age old problem, everybody does it and everybody gets away with it until that one day were two wrongs just happen to make a right and some one is dead.

ESD is real, it’s been killing people for years, we only just figured it out a few years ago. That’s why ECLI’s are now required on docks.

 

[STB]

I wish, in practice, ELCI were required on docks :-(

I worry as much about my shore power cord and it falling in as anything. (And, yes, I replace it every couple or few years). I have ELCI on my boat.