Mystery light on Classic

[ericjan2]

On the drivers side of my '77' 31' Sovereign I've noticed a 'light' about a third of the way up and about 4 feet from the bumper. It has a thick amber lens about the size of a quarter and on the inside below the twin bed it has about a four inch tube connected to the backside of the amber lens. Does anyone know what tis is for? I'll try to post pictures.

[4RXLA]

That’s a reverse polarity light that will light up if there is a problem with the electrical hookup. Leave it be.

[Wazbro]

Originally Posted by 4RXLA

That’s a reverse polarity light that will light up if there is a problem with the electrical hookup. Leave it be.

Correct, but I would disconnect it. Some have experienced hot skin when connected to an outlet with reversed polarity. Granted the power going to the skin is only what gets through the bulb so shouldn't be dangerous to most people, still can be concerning.

[ericjan2]

I don't really get it! Can you explain if you have a moment.....Thanks in advance

[Wazbro]

The light is wired from the neutral wire to ground. When polarity is reversed the neutral is hot and the electricity goes through to ground which is connected to the frame/skin of the Airstream. If the incorrectly wired outlet you're plugged into also has a poor ground the skin is electrically hot.

Also it may trip a GFCI circuit you're plugged into with the extra connection from neutral to ground.

[richard5933]

Originally Posted by ericjan2

I don't really get it! Can you explain if you have a moment.....Thanks in advance

It's to check the status of the incoming 120v power which you've connected to by plugging into the shore power outlet at the campground.

The incoming power has three conductors: the hot lead, the neutral lead, and a ground. Normally there would be power available by connecting a light to the hot & neutral OR the hot & ground. There should never be power available by connecting to the neutral & ground, and this bulb is set up to check that out.

Reversed polarity means that the hot & neutral wires in the shore power outlet you plugged into are connected backwards in the receptacle box.

[ericjan2]

Is there enough current in the skin, when there is a reverse polarity issue, to harm you? In other words, if I was standing on wet ground and went to open the door could I get seriously shocked by this condition? If so, will one of those new plugins with lights showing the status of the pole power be a worthwhile investment?

[Wazbro]

Originally Posted by ericjan2

Is there enough current in the skin, when there is a reverse polarity issue, to harm you? In other words, if I was standing on wet ground and went to open the door could I get seriously shocked by this condition? If so, will one of those new plugins with lights showing the status of the pole power be a worthwhile investment?

As long as you don't have an electronic surgical implant it "should" not be enough to harm you, the bulb should only let 5-10 watts through, enough to feel a tingle.

Regardless it is worthwhile to get a circuit tester to check before you plugin or better yet get an EMS (Electrical Management System=high tech surge suppressor that also protects from high voltage, low voltage and reverse polarity). There is a choice of a portable EMS that you plug in, then plug the cord into it every time and have a risk of theft or a built in EMS that you install once inside the trailer and can't forget to use.

[Al and Missy]

Originally Posted by ericjan2

Is there enough current in the skin, when there is a reverse polarity issue, to harm you? In other words, if I was standing on wet ground and went to open the door could I get seriously shocked by this condition? If so, will one of those new plugins with lights showing the status of the pole power be a worthwhile investment?

Yes, yes, and yes.

[kb0zke]

Several years ago I made a simple tester. Since my coach is a 50A coach, I used a short 50A plug and cord. Instead of the coach end, though, I put a square box with two outlets, one wired to each leg of the 50A. In each outlet I put a tester and a volt meter. When I arrived at a new campsite I would plug this in first. I instantly knew if it was wired correctly (the two little testers) and what the voltage was on each leg. Later I added a 250 VAC neon light wired across the two hot leads. If that lit up I knew I had 240 vac, even though I don't have anything that uses that.


Unfortunately, it spouted legs a couple of years ago. I need to make another one.