Getting a shock from the camper.

[Jeep]

Just wandering if anyone else has ever had this problem before or if anyone has an idea what the problem might be. I have a 1994 Rockwood 1910. When I have the power hooked up to the camper I get a slight shock off of the exterior access door to the refrigerator. I don't notice it anywhere else on the camper. I did look around that area and i don't see any wires that were chewed on or anything out of the ordinary. I have had the camper for about a year now and I did notice it last year but never looked into it because it was wet inside the access door when it did it before and I just thought that was the reason but it is bone dry now and still does it. This has me stumped.

 

[Raycfe]

Sounds dangerous .......... I keep a led 110 AC circuit checker in the PUP at all times. I would check the outlet the refrig is plugged into. My outlets are also all GFCI protected.


http://www.amazon.com/Electrical-Receptacle-Outlet-Ground-Tester/dp/B0012DHVQ0/ref=sr_1_7?ie=UTF8&qid

 

[joet]

I would be seriously looking at the grounds. The tester that Raycfe makes note of can be found in just about any store that sells electrical supplies . ( Lowe's, Home Depot)

 

[Jeep]

I will pick one of those up tonight and test the recepticles out. We are going on a trip Memorial day weekend so I better get crackin. I will let you know how I make out.

 

[Jeep]

Well I did get a receptacle tester and all the receptacles tested that they had an open ground. When I tested my homes receptacle that had an open ground so that's where the problem started. Only receptacle on my home that tested that way was the one I was plugged in to. I thought just plug into a good receptacle and all will be good but I was wrong. After plugging into a good power source when I tested the outlets in the camper again they now trip the GFCI receptacle as soon as I plug the tester into anything on that circuit. It seems odd because before the receptacles worked but just tested bad. Now with a good power source they immediately trip the GFCI. Am I missing something here?

 

[Wrenchgear]

What you may be missing is the original shock problem.

I know you were having a problem with the house receptacle you were using for power. I don't think that lack of ground was the problem making you to get a shock off the fridge. It may have been contributing but, there must be a problem with the wiring in the Pup, (fridge circuit or fridge itself). When plugging something else in, that feeds through the wiring problem and blows the GFCI.

 

[turtle]

The reason your GFCI didn't trip before was because there was no ground. With a propper ground the GFCI is now doing what it is intended to do. A light type tester is not likely to help find the problem as it is a very small voltage leak somewhere. I would start by pulling all 110v outlets (start with the refer) and make sure all wires have a good connection and there is no corrosion from moisture.

 

[Wrenchgear]

Yes... turtle is right about the GFCI not blowing because of the lack of ground.

 

[jckele]

A standard outlet tester, with 3 indicating lights, is not suitable for testing GFCI outlets. The standard tester uses two lamps to indicate proper outlet polarity. One lamp is from hot to neutral. The other lamp is from hot to ground. If both light the the outlet is wired correctly. The third lamp is wired from the neutral to ground. It should never light up unless the outlet is reverse wired. So the tester is actually working properly and I would suspect the GFCI outlets are also OK. A GFCI outlet measures the current leaving the hot and compares it to the current returning on the neutral. If they are not identical the some current went else were. Where, probably to ground, so to prevent electrocution the GFCI will trip. Now when you use the tester and two lamps light, one to show polarity and the other to show proper ground, you have twice the current from the hot but the neutral only has half cause the ground is taking the other half. The GFCI is doing it's job by tripping.

A proper GFCI tester, which will also work on standard outlets, has special internals to allow proper testing of a GFCI without tripping it. It also has a test button for tripping the GFCI.

I hope this helps

 

[jckele]

By the way a GFCI will operate properly with or WITHOUT a proper ground. The device simply looks at the currents in the hot and neutral. If they are not the same then the current must be going some where else and the GFCI will trip.

In Ontario cfgi outlets are used to replace the old 2 prong outlets in older homes. It is required by law where a ground is not available at the outlet and a 3 prong outlet is desired. It does not provide a ground and is marked as such but the cgci functions properly and allows the use of 3 prong devices.

 

[Jeep]

Thanks for all the help everyone! I did figure out that this tester has a GFCI button on it that you hold down when testing GFCI circuits. I also found that when I am plugged into the receptacle with the bad ground I was getting a reading of 7 volts coming off of the access door and when plugged into a good grounded receptacle I am not getting much of anything at all. For whatever reason I can't replicate the shock that I was getting before even when I plug into the bad ground. I can't feel a thing from only 7 volts but I know before it had to be more than that because I could feel it. Is it safe to say if I plug into a good grounded outlet it is safe for me and my family? I have went over every wire and receptacle and everything looks good. All the insulation, wires, and the connections on the receptacles look good.

 

[David in MI]

Ok, re write because most of what I wrote jck beat me to lol

NO you are not good to go.

where are you measuring 7v? from the door to what and is it ac or dc?

Are you plugging in to a GF protected circuit on the house?

the 7v reading tells you there is a short - that it seems to go away with ground shows you that grounding is a good safety feature.

I had assumed you were on a gf house circuit but now I don't think so as it should trip when you plug in. (unless your 7v is dc) Try running an extension cord to a gf outlet if you have one around.

Anyway you need to find your short - if your getting hot from the access door, try the trailer hitch or other bright metal on the frame. I'll bet it's hot too.

 

[Jeep]

Yeah I was measuring the 7 volts from the access door to the ground. Actually though I was getting the same reading off of everything metal in the refrigerator compartment. I also unplugged the fridge and had the same reading. This was all when I was plugged into the receptacle with the open ground. Looks like I may have to cancel my trip this weekend if I can't find this short. Long day at work tomorrow for me but I will go over everything again when I get home and maybe see something I missed before. Thanks again for the help everyone.

 

[David in MI]

Is the 7v ac or dc?

If it's DC you are ok - you should still look for the short in your dc system, but it's not the safety hazard that AC is, and it explains why you aren't tripping gf on your shore line.

Most Pups have 2 electrical systems - maybe three I'm not sure if the tow lights are normally Isolated from the camper system or not.. For sure there is a 12v DC system and a 110v AC system. There is usually a deep-cycle battery located near the power inlet with a charging system. On mine I believe the lights are all 12v and there are 110 outlets. All of this is going to ground out through the frame and on out through the shore line when it is connected with a good ground.

Fridge's are often 2 or even 3 way powered. Even though you unplugged yours (ac i assume) you may have left the dc connected, or it may just be that you have a dc short in that area and it's not in the fridge itself.

 

[jckele]

1 st things first. Disconnect all power, AC / DC and tow vehicle .

Using a dvom check to see that the frame of your trailer is indeed connected to the ground pin of the male AC plug. It should read the same continuity that you get if you short the meter probes together. If you are testing using the continuity "beep" setting on the meter then your doing it wrong. Set the meter to the highest impedance scale, typically the meg ohm range. Be sure to isolate yourself from the probes, frame and plug cause you will induce a false reading. You could also use a high K ohm scale. Your reading should be close to zero ohms just like if you touch the probes together. Also check the frame of the fridge to ground, connected but no power of course. It also should be zero. If not then proceed to check the grounding conductor that usually runs from your AC panel through the floor and bolts to the frame. They often rust at the frame.

If your continuity readings are OK then I suggest that you specifically test the fridge AC cabling. You indicated that you can unplug it so I suggest that you check continuity from ground to hot and then ground to neutral on the male plug. Be sure to isolate yourself, no touching the probes or parts of the plug with your fingers. It will induce a false reading. If you stick a probe lightly into each thumb you will see the meter respond! You don't want this. Anyway, both readings should be infinity. The meter should show the same as if you just held the probes apart in the air. If you get any other indication or a continuously changing reading then there is some problem within the fridge or its cable. Checking continuity from hot to neutral on the male plug will give a reading which is normal and that reading is of no concern.

Give it a try but BE SURE TO DISCONNECT ALL 3 POWER SOURCES
you could damage the meter and yourself!

 

[Jeep]

Good news I think... I put my meter on the 2000 K ohm setting and tested the male ground on the camper plug to the frame of the camper and there was no change on the meter at all. Everything else tested ok. I did the receptacle that the fridge plugs into as well as the wire that plugs into the receptacle for the fridge and all is good. So I found where the ground wire is connected to the frame and it was rusted up. I took out the screw that connects the ground to the frame, replaced it with a new one and I also sanded the connector on the wire and sanded the frame where the ground touches it. I put it back together and now I am getting the correct reading of 0 from the ground plug to the frame. Then I hooked the power up to the camper from my good grounded outlet and I kept the meter on the same setting and went from the access door to the actual dirt I was standing on and had a reading right around 250. Not sure at all what this means but I then did the same test but from the ground of the extension cord plugged into the house to the dirt and had the exact same reading. Is that normal? I'm not even sure if that test that I did means anything at all but its making me think that my house has some issues with the wiring? Oh by the way I have no battery on my camper at all so it is all ac power I guess except for the 12 volt lights that work off of the convertor.

 

[jckele]

Hey, glad you found the problem, I sort of figured the frame ground was the culprit. Testing from ground to "earth" won't really tell you much. You said your meter read 250 x 1000 = 250,000 ohms. Its very high but certainly nothing to worry about. Your home ground is most likely connected to the incoming copper water line from the city or a pair of 10 foot ground rods.

Poking and testing ground in the earth will give unusable results. Put a little water on the ground and see what happens. The reading will go down maybe to 100,000 ohms. The only true method to test your home ground is with a megger or other sophisticated equipment. But this is not what you were trying to repair. ( little off topic)

It`s a good idea to check the frame ground every year.

Remember : The ground is the most important part and needs to be in good working order to deal with any faults that may occur in the system. A poor or removed ground can lead to property damage , electrocution, and even death.

 

[Jeep]

Thanks a bunch for the help and for saving my camping trip this weekend everyone! I feel much better now knowing the electrical system is in check when I have my 5yo and 6 mo children in the camper. I wasn't too worried about my wife! Thanks again.

 

[tsc]

Not sure if this is a good idea or not, but my father in law, always paints over the ground with a light coat of rust paint, once it's secured, (a different colour then the frame). He says it will prevent it from rusting/corroding.