Need Help Quick - 110v Reverse Polarity Indicator is On

[Pat Anderson]

OK, Patty brought the boat back from Bellingham, ready to head to Powell tomorrow after work. Hooked up shore power as usual - instead of the green light on the 110V panel under the dinette, the red reverse polarity light is on. It is not our house wiring, because I got the same result plugging shore power into the Honda 2000i...what is it, and how do I fix it? Thanks!

 

[Sneaks]

New or different power cord? That's about the only way to get an "instant" polarity reversal if it was working before.

If it is a different cord, it's time to check it for a miswired plug or socket.

Don

 

[SEA3PO]

That's what I found in my house.... some plugs had the correct polarity and a couple diden't....so everytime I plug in my boat I need to check...I think it might be in the power box of the house...

I just hunt around until I find a good hook-up... darn old houses...

Joel
SEA3PO

 

[rogerbum]

Or maybe you're plugged into a different outlet at home? Other than that, as Don indicates, it would be hard to get the polarity reversed without something changing - cord, outlet etc.

 

[journey on]

When I plugged Journey On into my daughters house in Redondo Beach, the red light came on and everything shut down. Since it had worked in other places, I had her try plugging it into other circuits, not just a different plug. Found one circuit/outlet that worked.

As said above, if there were no changes, you may have plugged into a different plug. Remember, houses are wired by low bidder, and they work fast. Somewhere they interchanged the power and return wires going to a plug.

Boris

 

[Sneaks]

Remember, houses are wired by low bidder, and they work fast. Somewhere they interchanged the power and return wires going to a plug.

Boris

It ain't just builders, Boris. I lost BOTH landlines early today and there's still no dial tone on either one. The freaky part? My DSL is still working just fine. Knowledgeable neighbor says there's a ring-tip reversal somewhere. Cynical Don sez it's a low bidder AT&T subcontractor.

 

[Pat Anderson]

Same power cord. And I just reversed the hot and neutral leads on the plug on the power cord - reverse polarity light is still on, but all the 110v circuits, including the battery charger, seem to be working. I am fairly bewildered here...I guess if the 110v circuits are working, it really doesn't matter much if the reverse polarity light stays on?

New or different power cord? That's about the only way to get an "instant" polarity reversal if it was working before.

If it is a different cord, it's time to check it for a miswired plug or socket.

Don

 

[marvin4239]

I'd insure the power cord is wired correctly then turn off the main breaker and the branch circuit breakers in the boat. Plug the cord back in check the light and then turn on the main and check the light. Then turn on the individual breakers one at a time checking the light. Perhaps it's something in your boat causing this.

 

[Sneaks]

Same power cord. And I just reversed the hot and neutral leads on the plug on the power cord - reverse polarity light is still on, but all the 110v circuits, including the battery charger, seem to be working. I am fairly bewildered here...I guess if the 110v circuits are working, it really doesn't matter much if the reverse polarity light stays on?

OK, if it were me, I'd:

Rewire the known good cord back to where it was when you first had the problem, then run down to your local Home Depot and buy a cheap polarity check device. The device is small, plugs into a socket and has three LED's showing either that it's wired OK or there's a problem and what it is. Plug that device into the house socket, then the end of your extension cord, then if there's no problem, plug it into the boat's convenience outlet. If it too shows a reverse polarity, you've got a problem that's gonna need a real electrician. If it shows things are normal, then it's likely the fault sensing device on the boat has a problem and you can safely ignore the red light until you get it somewhere for a fix. The polarity check plug is a handy test tool. Especially for old homes.

My, Pat, you sure do attract the unusual....

Don

 

[Captains Cat]

My, Pat, you sure do attract the unusual....

Don

I second that! Remember the lug nut incident :?:

Pat, let me send my granddaughter out there. She knows how to program VCRs too! I OTOH, finally got the clock on the VCR to quit blinking! A small piece of black plastic tape did the trick!! :?

Like some of the others, I suspect the outlet that you're plugged into rather than the boat/shorepower cable if nothing else changed.

Charlie

 

[captd]

All things the same , I would say your indicator light is shorted out.
Use volt meter and check receptacles on both ends (boat and source.) If you don't have a cheap plug in tester.
captd

 

[Sneaks]

I second that! Remember the lug nut incident :?:
Charlie

At least my fine upstanding nephew has never fallen in the water at the dock, Charlie. He may be technically challenged but he doesn't have syndrome O6 complicated by age related issues....


:wink :thup :thup Ptbbbtttttt

Don

 

[Bad Boy]

Same power cord. And I just reversed the hot and neutral leads on the plug on the power cord - reverse polarity light is still on, but all the 110v circuits, including the battery charger, seem to be working. I am fairly bewildered here...I guess if the 110v circuits are working, it really doesn't matter much if the reverse polarity light stays on?


Please take your problem seriously.

If your power cord was correct before, I suspect you may not fully understand AC circuitry. When you changed the polarity on your power cord, the hot circuit from your house now travels through your mis-wired power cord to your AC panel through the neutral side. The 110vac circuits will still work, you can still use breakers to shut off your circuit and your breakers will still trip. However, you still have a major problem. Even if your breaker were to trip (remember, now it will trip on the neutral side), your hot line will burn up if you develop a short between the hot and ground = fire!

My appreciation for all of this originated from an incident thirty years ago when a friend of mine put a new power cord on a drill with a metal housing. He thought it didn't matter whether the neutral and ground wires were reversed. He was barefooted when he pressed the trigger and was electrocuted! He originally thought the drill was malfunctioning because it needed a new cord. He did not know there was a short in his drill motor. So, when he pressed the trigger, the electricity went to the metal case (which was now the neutral leg) and he was electrocuted.

Similar caution should be made when there is a reversal of the hot and neutral legs ("reverse polarity"). When your Honda generator also indicated reverse polarity, it should have should have put up a flag. When you reversed the wires on your power cord and it did not resolve the problem, it should have put up a flag. It should have been a simple matter to check the continuity from one end of the power cord to the other, in the proper location, to determin if the problem was your power cord. Reversing hot and neutral wires on the plug end instead of checking with a continuity tester indicates to me that you may not fully understand an AC circuit. Although I applaud your desire to fix things yourself, get someone to give you on-site training first.

My reply here is not to insult or trouble shoot through the internet, but to convince you that that are so many things to consider. Unless you fully understand the relationship of all three legs on an AC circuit, it can be a deadly mistake to think everything must be okay if your 110vac circuits are working. What others are trying help you with may not register the same to you and you may trouble shoot opposite of what was intended. Please have a qualified person trouble shoot the system for you and learn from him.

 

[Da Nag]

Please have a qualified person trouble shoot the system for you and learn from him.

Amen.

Pat - please be careful here. Les has often stated that shore power is the most dangerous system on a boat, and your posts here are making many of us nervous.

Please ensure a qualified professional signs off on things before using your shore power...I'm sure I can speak for all your Brat buddies, when I suggest we'd prefer to see you at the SBS again this year.

 

[Pat Anderson]

Well, I bought a polarity checker at Lowe's. But the boat is not here right now, it is at Mann's Hitch and Trailer for brakes and bearings. I can check the outlet and extension cord, and will check the outlets onboard when the boat comes back. I will swap the wires on the plug back to what was the known good condition (worked for three years). So my assumption is that if the outlets onboard show correct polarity, then the reverse polarity light on the panel is probably the culprit. We will not be using shore power at Lake Powell anyway, and if I cannot figure it out with these fairly simple measures, I guess I will take it to LUSR and have them do it.

 

[marvin4239]

Pat as others have said please be careful with this. On another note do you have anything plugged in to the boats receptacles or have you recently installed any new 110 volt equiptment that could be bad? Just food for thought.

 

[Bad Boy]

We will not be using shore power at Lake Powell anyway

Pat,

If you use your 2000 watt generator, there is still the same danger.

Hopefully, your problem will be resolved quickly and you can enjoy your trip at Lake Powell.

 

[drjohn71a]

Pat,

This type of thing happened to me many years ago in the mid '70's with a van camper at a campsite. I actually ended up getting a pretty good shock out of it. Turns out some flooding had gotten into the campground's wiring system allowing stray currents.

that was long ago, but worth a look at the possiblility of water in a conduit or a leaking underground cable, etc..

'hope you make it OK to your planned cruise!

John

 

[thataway]

Glad you have the reverse polarity light now. The other tools to have are digital volt meter, as well as a Kill-a-watt meter...(some folks like a 12 volt test light, I just soldered a set of leads to a small 12 volt bulb.

The Honda Generator (the inverter series) will always give a reverse polarity light, as will inverters, --since they run thru the inverter, instead of running a pure AC circuit.

Unfortunately many docks (and houses) are miss wired. I have also found a number of RV outlets which were misswired.

 

[eNORMous]

I'm not a certified electrician (just to make that clear). However, I do know it's the amperage which will kill you. You're talking a minimum of 30A I assume. Whatever you do, DO NOT work on your reverse polarity issue while the boat is in the water. Also, most reverse polarity indicators (occupying the void between the neutral (white) and the ground (green) wires) displays the differential between these two wires and the light will glow proportional to the length of the cable and/or proportional to the amount of load placed on your neutral bar. If it's fire engine glowing - you're loaded up, if it's a soft glow (as can often be the case), it is less of a concern - but rightfully still can be of concern. I know many folks who get reverse polarity employing battery chargers and/or generators for several reasons: (1) the auto and cheap battery charges do not separate their fields appropriately and load up the neutral bar on a boat (this is very bad);and, (2) the inverters are inadequate or misaligned with the inverters in many boat systems - causing once again a load to manifest on the neutral bar of the boat's electrical system.

Finally, on one old boat I had, corrosion was buiding up and simply cleaning all battery terminal post leads (to the bus bars and to the batteries) cleared up the issue with the reverse polarity. That one was easy to figure out, since I saw the glow progressively get stronger and stronger over time, leading me to conclude reverse polarity was "building" rather than just "appearing".

Curious to know if it's glowing hot or a subtle glow on the reverse polarity indicator?

Norm