Reversed Polarity?

[SilverRanger]

When we arrived at Perry and hooked up our 2005 Bambi to the 30 amp service, everything seemed to be working except the AC, so I checked the circuit breaker and found the breaker tripped. I reset it and everything performed flawlessly. I can't recall ever having to reset the breaker in the two years of owning the trailer.

A few hours later, when the volunteer crew came around to check the electrical connections, the advised that the polarity was reversed. They checked it at several outlets with both a voltage meter and a simple polarity tester. Then they checked the 30 amp source, which showed correct polarity. I also verified this with my own polarity tester, which I routinely use to check for the correct connections at campgrounds and in the unit. Nothing like this had ever happened before. At one point, they were considering unhooking me until I had the problem corrected, but since everything was working OK, they allowed me to remain connected.

I heard that Airstream had sent service technicians to the rally, so I visited them the first thing in the morning to ask if they had any ideas on how this could happen. The service advisor seemed very concerned that this could happen in a two year old trailer and asked if I wanted them to check it out. I accepted, but advised the warranty had expired two weeks earlier. He said "Never mind that, we have to make this thing right"!

As you can imagine, with nearly 1000 Airstreams on site, they were pretty busy, so we set up an appointment for the next morning. Two techs actually showed up a few hours later that same day with testing equipment and tools in hand. When they checked it, they said the polarity was correct. They checked all outlets, inside and out, with the same results. I checked it again with my own tester and the polarity showed as correct. One of the techs noticed I had a fairly sophisticated automatic power supply with a constant voltage readout display that I use for my computer equipment, so he advised me to keep an eye on the campground voltage fluctuations, and then took the time to give me a basic primer on circuits, fuses, and breakers. He also said that if the polarity was truly reversed, the GFI near the bathroom sink, which controls all but one outlet, would have immediatley tripped, but offered no theories on how this situation could have happened, or self-corrected. Needless to say, I was relieved (and very impressed with Airstream service), but still wondering if this could happen in the future.

Any theories on how this could have happened?

[overlander63]

Originally Posted by SilverRanger

Any theories on how this could have happened?

...Sunspots?...
Seriously, did y'all unplug the trailer at any time between the two check-overs? It's possible something electronic got up on the wrong side of its electrical bed, and when you unplugged, it righted itself. Bad explanation, but maybe the polarity reversed in the converter, the a/c compressor started backwards, maybe a plug on a hairdryer was reversed.


on edit, I just looked at the plug on the charger for my laptop, and this almost new item DOES NOT HAVE A POLARIZED PLUG. Maybe it is that simple.

[Poprivet]

I'm under the impression that the only things affected by A/C reverse polarity is electrionics. A/C, alternating current, actually reverses the polarity sixty time a min. A reverse polarity condtion in A/C refers to the phase voltage with respect to the ground I suspect the problem you posted was related to a low voltage condition and not reverse potarity. Low voltage would have caused the current drawn by your AC unit to increase and popping the breaker.

[Silvertwinkie]

I'm not sure if this is the same thing, but I noticed recently that when power issues happen like what you describe, the outer skin sometimes has voltage on it....not much, but we recorded 38 volts DC.

[dwightdi]

Most likely the problem was the voltage was low and popped the breaker and the volunteer crew were mistaken about the polarity switch. Their polarity tester could have been defective or they did not operate it properly. I would trust the Airstream repair team which is usually more trained than the volenteer WBCCI crew.

[SilverRanger]

Originally Posted by overlander63

...Sunspots?...
Seriously, did y'all unplug the trailer at any time between the two check-overs? It's possible something electronic got up on the wrong side of its electrical bed, and when you unplugged, it righted itself. Bad explanation, but maybe the polarity reversed in the converter, the a/c compressor started backwards, maybe a plug on a hairdryer was reversed.


on edit, I just looked at the plug on the charger for my laptop, and this almost new item DOES NOT HAVE A POLARIZED PLUG. Maybe it is that simple.

Thanks, Terry. The trailer remained plugged in until the AS techs checked it the next day. I hadn't considered devices with non-polarized plugs as a possible cause. The only thing I may have had plugged in was a tiny LED night light, which is non-polarized, and the voltage converter brick for the LCD television, which is polarized. My wife forgot to bring her hair dryer. (With the heat, she discovered all it took was about a five minute bike ride to dry her hair.)

At this point, sunspots may be the best answer.


David Alan,
"Low voltage would have caused the current drawn by your AC unit to increase and popping the breaker."

The AC unit was off when I plugged in to shore power ,and the breaker was apparently tripped prior to turning it on. I always keep the system off until plugged in, and after a voltage check, which was at 109 volts. The entire time we were there the voltage stayed mainly between 109 and 117 volts.

Thanks.

[SilverRanger]

Originally Posted by dwightdi

Most likely the problem was the voltage was low and popped the breaker and the volunteer crew were mistaken about the polarity switch. Their polarity tester could have been defective or they did not operate it properly. I would trust the Airstream repair team which is usually more trained than the volenteer WBCCI crew.

Dwight,
A faulty tester was my first instinct too, but the three man volunteer crew each had their own tester, one of which was a multi-meter, and I verified it with my own tester. I fully agree that the AS team were better trained and equipped, but I'd say the odds of 3-4 testers being faulty are pretty slim.

Thanks.

[Poprivet]

[QUOTE=David Alan] "alternating current, actually reverses the polarity sixty time a min."
Opps, I 'mean "60 times a second"

Electrical problems that do not repeat are generally caused from something external. Any chanch there was a concurent electrical storm?

Did you try Airstream Help? Perhaps someone in India would tell you to turn it off for 5 min and re-boot.