REVERSE POLARITY WHEN ROOF TOP AC COMPRESSOR COMES ON

[cyberjerkx]

SO WE STARTED NOTICING WE WOULD GET A SLIGHT SHOCK WHEN TOUCHING ODD THINGS LIKE WASHING HANDS IN THE SINK. TONIGHHT I LOOKED AT OUR SURGE PROTECTOR AND IT READS ONE RED AND ONE GREEN LIGHT REVERSE POLARITY. I CHECKED THE PLUG, ITS WIRED RIGHT TURN OFF THE AC AND IT GOES BACK TO NORMAL. TURN JUST THE FAN ON THE AC STAYS NORMAL. BUT AS SOON AS I TURN IT TO COOL AND THE COMPRESSOR KICKS ON IT READS REVESED POLARITY.
I WORK WITH ELECTRICAL SYSTEMS AC AND DC, I KNOW A FAIR AMOUNT EVEN REWIRED A MOTOR OR TWO. I HAVE LOOKED AT THE WIRING OF THE AC DOSENT LOOK LIKE A WIRING ISSUE, BUT I DONT HAVE A SCEMATIC RTO BE 100 PERCENT SURE. THERE IS ALOT OF WATER COMING FROM THE AC UNIT. BUT IT ONLY HAPPENS WHEN THE COMPRESSOR KICKS ON. IS THE COMPRESSOR WORN OUT OR WIRED WRONG, HOW CAN I TROUBLE SHOOT THIS FURTHER AND FIX THE PROBLEM

 

[Rene T]

Welcome to the forum.
Please don’t type your posts with caps turned on. For some people it gives the impression that you are shouting.
Has anyone worked on it recently and has it ever worked right?
I don’t know if this would do anything but have you tried to plug the rv cord into another receptacle?

 

[Rene T]

Where do you see the water. Is it outside running off the roof or inside?
What is the make and model of the air conditioner?
How old is it?
Please try to answer all the questions I’ve asked.

 

[SeilerBird]

I refuse to read all caps. Very rude to shout at us.

 

[Gary RV_Wizard]

Is this a 50A RV? A faulty neutral wire on the shore power connection lets the hot wire voltages float and can cause all sorts of flaky things. But a open neutral wouldn't usually get past the surge protect device either.

Please state whether the RV electrical system is 30A or 50A and what source it is plugged to. Also the make & model of the "surge protection device" (some are more capable than others). Make & model of the RV is always helpful too.

 

[John From Detroit]

Sounds like an open neutral and/or safety ground to me
First on an RV there is a LOT of Romex.. Romex (2 wire plus ground) is actually a very good capacitive voltage divider. If the ground is open it's 60 volts. High current loads might (I do not know without more research) increase this tendency. That's why the safety ground is IMPORTANT.
Add to that a weak neutral can make it worse.. And you get knocked on your...er... pride.

 

[Kirk]

I have been an electrical worker for may years but don't understand how you can look at it and see if something is reversed? As Gary said, you really have not given us enough information to do more than just guess. It sounds like a failure in the compressor or it's control circuit. If we knew what RV and what make and model of air conditioner that would help.

 

[Old_Crow]

I have been an electrical worker for may years but don't understand how you can look at it and see if something is reversed? As Gary said, you really have not given us enough information to do more than just guess. It sounds like a failure in the compressor or it's control circuit. If we knew what RV and what make and model of air conditioner that would help.

He said his surge protector indicated reverse polarity in the second sentence of the all caps post. Mine will do the same.
To me that indicates the problem is in the pedestal, not the RV.

 

[Contributor]

First thing I would do is take a look the AC water issue and possible wires immersed in it. Could be a ground wire and a neutral wire are soaking in a puddle and current flowing between them. That may explain why you get shocked when touching things.

Look for loose connections on all the wiring to the AC unit.

 

[Frizlefrak]

He said his surge protector indicated reverse polarity in the second sentence of the all caps post. Mine will do the same.
To me that indicates the problem is in the pedestal, not the RV.

I would agree, except all is well until the compressor engages. If the compressor itself is isolated from the circuit, polarity is correct.

First thing I would do is take a look the AC water issue and possible wires immersed in it. Could be a ground wire and a neutral wire are soaking in a puddle and current flowing between them. That may explain why you get shocked when touching things.

Look for loose connections on all the wiring to the AC unit.

Bingo. This is the first thing I would look for. Also look for pinched wires that are leaking current to ground or neutral, screws through insulation, etc.

The "slight shock when washing hands in the sink" would scare the bejesus out of me, and I wouldn't use the RV at all until this problem was identified and corrected. Current is obviously leaking, and the A/C compressor or something in it's proximity it obviously the culprit. Knowing if 30A or 50A would be helpful in troubleshooting.

 

[cyberjerkx]

its a 30 amp plug on a 1976 40' pioneer 5th wheel. thye water is coming from the ac driping off the roof, its been 110+ here so the ac is being ran about 20 hours a day

 

[Rene T]

its a 30 amp plug on a 1976 40' pioneer 5th wheel. thye water is coming from the ac driping off the roof, its been 110+ here so the ac is being ran about 20 hours a day

That water is normal. It is taking the humidity out of the air and it will run across the roof to a rain gutter then down to the ground.

 

[John From Detroit]

Ok, what is "Reverse Polarity" to the surge protector.. (Voltage between Neutral and ground of course is seen as Reverse Polarity)
As I said the wires in The RV form a capacitive voltage divider. Now open ground will be 60 volts (1/2 the line voltage) but a weak ground might be different. and it's possible the higher current may affect it or rather affect the amount of current the divider will pass.
The Surge guard sees it as "Reverse Polarity"
I had a like problem in one CG. Guard indicated as I recall Open Ground.. turned out to be poor neutral connection per the technician (Parks as it was not my problem) who fixed it.

 

[Kirk]

He said his surge protector indicated reverse polarity in the second sentence of the all caps post.

And he also said that it doesn't happen until the compressor turns on.

its a 30 amp plug on a 1976 40' pioneer 5th wheel.

As Rene said, the water off of the roof is as it should be. What I don't understand is that you say the surge protector reads reverse polarity but doesn't it then turn off the power? What make & model is the surge device? If you get water from the roof the air conditioner must continue operating?

If you are getting a shock when you wash your hands, you must have what we call a hot skin condition and that is very dangerous! It may or may not be related to the air conditioner problem but would be related to a reverse polarity in most cases.

Have you got a reliable meter and have you taken any readings with it? If you have, what were the readings and where were they taken?

 

[Frizlefrak]

its a 30 amp plug on a 1976 40' pioneer 5th wheel. thye water is coming from the ac driping off the roof, its been 110+ here so the ac is being ran about 20 hours a day

The water coming off the roof is condensation, and is normal....unless it's collecting inside the A/C unit to the degree that it's shorting the compressor. This is possible if debris has built up over time. Given that we're talking about a 46 year old unit, which has probably had the compressor replaced (incorrectly) at some point, it's very likely that either the relay or the compressor itself is wired incorrectly, or a bare hot wire is touching the body of the A/C unit. As Kirk mentioned above, it's creating a "hot skin" condition. THIS CAN BE FATAL.

If you're unable to troubleshoot and correct this problem, please stop using the trailer and have it serviced by a professional.

 

[Old_Crow]

And he also said that it doesn't happen until the compressor turns on.

My thought was a crappy connection that doesn't show the reverse polarity until under an increase load.
I didn't think the surge protector would show a problem with the coach, though. I thought it was designed to detect problems in the pedestal.

 

[Kirk]

I thought it was designed to detect problems in the pedestal.

You have it right. But we don't know what "surge protector" he has but from his discription I am guessing that it is one of the power monitor types. All of those that I am familiar with interrupt power if there is reversed polarity so the air conditioner would stop. I wish that he would tell us exactly what power protection device he has and the make/model air conditioner as well as a few voltage and resistance readings. With that we could probably give some help. What I consider most concerning is the electric shocks.

 

[Gary RV_Wizard]

If the surge device recognized a reverse polarity condition to know it should turn on the indicator lights, I would expect it to complete its normal action for that fault. Since it did nothing else, I'm wondering what type of device it could be?

Update: Looking at the instructions for the very basic Surge Guard #44260 & 44270, it has indicator lights for Reverse Polarity but I see nothing in the Op Manual that says it shuts power off. It merely "indicates faulty park power". The more expensive models do more, but these are just surge supressors with power status lights.

 

[Contributor]

If it was me, I would get on the roof, take the AC cover off and inspect everything. It is a very easy thing to do. I understand that condensate forms but the drain could be plugged.

THERE IS ALOT OF WATER COMING FROM THE AC UNIT

Also examine the capacitors and all wiring for snugness and correct color coded connections. It's a half hour job. I would think that if he suspects the pedestal, he could verify it by plugging into another one.

The fact that he gets shocked when touching things indicates a wiring problem, not a pedestal one.

 

[Old_Crow]

If the surge device recognized a reverse polarity condition to know it should turn on the indicator lights, I would expect it to complete its normal action for that fault. Since it did nothing else, I'm wondering what type of device it could be?

Update: Looking at the instructions for the very basic Surge Guard #44260 & 44270, it has indicator lights for Reverse Polarity but I see nothing in the Op Manual that says it shuts power off. It merely "indicates faulty park power". The more expensive models do more, but these are just surge supressors with power status lights.

Yeah, the basic Surge Guard is what I have and it was the operation of that one that I based my comments on. I figured since his unit didn't shut down the power, it is probably similar to mine.