Trouble at State Park

[TC_Z]

We have a 50A class A, we were going camping at a state park in Kentucky. It was hot so we were running the generator w AC on. We backed into our site, turned off generator, plugged in to 30A post using 30-50A adapter. Everything was fine but the AC would not work. I unplugged, started generator again, AC worked fine. I turned off generator and plugged into 30A post again. AC still would not work. I suspected the 30-50A adapter. I used volt meter and confirmed there was 120V on both hot legs of the 50A adapter outlet. I checked my disconnect switch with volt meter, showed 120V. After further trouble shooting I finally determined that the post 30A was wired wrong. The hot and neutral leads were reversed. Looking at the outlet with the round ground lug at top the hot leg is supposed to be at 7 o'clock, neutral at 5 o'clock. They were reversed. So the 30-50A adapter was splitting neutral instead of hot. I checked the site next door, it was good. So not only were they reversed, but also inconsistent. Ranger let me move. I am stunned to think how many years it has been wrong like this. Folks with 30A rig probably would't notice. Perhaps some with 50A rig were okay too, but not me. I now have a dedicated outlet checker in the cord compartment to easily check the post wiring before I set up and plug in. Another lesson learned the hard way...

[JRscooby]

wa8yxm wrote:
YOu said with the polarity reversal on teh box the A/C did not work.

The thing is. UNLESS you have somethign like a Progressive EMS or a TRC Surge guard which would have told you on it's face (or remote) what the problem is.. The A/C really does not care about polarity. No AC (Alternating current) device cares about polarity.. The issue is important only for YOU...

WHY. Well AC current flows the same no matter how you wire it up. but if it's backwards the danger of shock to YOU goes up. Seriously UP But the device actually can not tell unless (Like the Progressive Industries EMS) it is designed to do so

But a GFI will not always work with right with reversed polarity...

[wa8yxm]

YOu said with the polarity reversal on teh box the A/C did not work.

The thing is. UNLESS you have somethign like a Progressive EMS or a TRC Surge guard which would have told you on it's face (or remote) what the problem is.. The A/C really does not care about polarity. No AC (Alternating current) device cares about polarity.. The issue is important only for YOU...

WHY. Well AC current flows the same no matter how you wire it up. but if it's backwards the danger of shock to YOU goes up. Seriously UP But the device actually can not tell unless (Like the Progressive Industries EMS) it is designed to do so

[ItsyRV]

It seems to be a common mistake especially when a person or electrician isn't familiar with the 30 amp RV plug. They see the schematic and know which side each wire goes until they turn it around to connect the wires and forget that left is now right and right is now left. At least you weren't the first user who discovered the dreaded 30 amp 220 volt mistake.

[azdryheat]

Did you report what you found? Perhaps there are more pedestals wired wrong.

[Fulltimers]

Similar thing happened to me. The park only had 30 amps so I used my adapter to plug in my 50 amp motorhome. My tester said hot and neutral reversed. I told the park and they said no one else has complained and there was someone there before me and everything worked fine. Since I mad the adapter myself I simply reversed the wires in my adapter and all was well during our stay.

[2oldman]

I don't think voltage was the problem.

[Lwiddis]

I’m unaware of any experienced RVer that doesn’t check the power prior to plugging in.

[doxiemom11]

We always check our connection before plugging in and have a progressive industries surge protector that will cut power to the rig for both low and high voltage issues. It has saved us a couple of times.

[ReneeG]

In the many years we've been RV'ing we've seen this at least three times.

[cavie]

This is a prime example why you should always check the voltage before plugging in. Good reason to use and EMS. At the very least a simple surge protector. Or a volt meter if you know how to use one. Apparently you know how to use one. Just do it before you plug in.

[2oldman]

Excellent. I would have suggested that you needed to wait about 5 minutes between switching power for the air to come back on, but it looks like that's not it.

I didn't think polarity mattered, but in your case I guess it does.

Good job.