Trailer frame electrified?

[wbarnes]

Hi,

I have noticed that when hands are wet and I touch the frame of the trailer or the stairs; I will feel a very minor tingle sensation (similiar to when you stick your tongue on a 9volt battery; but much much milder).

Its almost unnoticeable, and like I said, your hands need to be wet to detect it.

Is this normal? I am wondering if it has anything to do with the fact that the negative lead of the battery is attached to frame.

I am plugged into 30amp electrical service and the battery is also hooked up and charged. I have checked the 30amp service with a multimeter and have confirmed that I get 120v across the ground and hot lead and 0 volts (certainly less than 1v) across the neutral and ground.

Any thoughts?

Bill

[RVhiker]

Originally Posted by wbarnes

... I have checked the 30amp service with a multimeter and have confirmed that I get 120v across the ground and hot lead and 0 volts (certainly less than 1v) across the neutral and ground...

Any thoughts?

Bill

The tingling is definitely not normal and may indicate a dangerous situation. Did you check the 30 amp service at the campground service box? Or did you check the service inside your trailer? Or both?

The readings look normal to me. But if you checked it at the service box -- certainly the first place to check -- did you also check the AC within your trailer? There could be a problem in the umbilical, the plug, or the umbilical installs in your trailer. So I'd suggest taking those readings from an outlet in your trailer.

[Grumpy]

We had that in FL one year and the main feed from the transformer to the CG had to be replaced. We were without power for about 8 hours.

[labracorn]

Disconnect right away you have a problem.We had that problem at our dog show and only lost a dog that night.I felt a tingle when I touch the trailer and dog fence.I disconnected rec. lucky the owner was ok.

[Jmooney]

RV 110v electrical systems are different from home systems. The Neutral ( white wire) and ground (bare copper) do not share the same buss on your power distribution center. This is to prevent any accidental electrocution should the Positive side of the 110 V come in contact the with metal frame of the RV.


The 12vDC, however, does share ground with the frame of the trailer.


I agrees with the previous remarks that this indicates a dangerous situation and is likely related to a ground issue with the shore power connection. I'm wondering if you are getting some low AC voltage reference to ground through the frame and the converter.

[Murff]

Originally Posted by Jmooney

RV 110v electrical systems are different from home systems. The Neutral ( white wire) and ground (bare copper) do not share the same buss on your power distribution center. This is to prevent any accidental electrocution should the Positive side of the 110 V come in contact the with metal frame of the RV.


The 12vDC, however, does share ground with the frame of the trailer.


I agrees with the previous remarks that this indicates a dangerous situation and is likely related to a ground issue with the shore power connection. I'm wondering if you are getting some low AC voltage reference to ground through the frame and the converter.

+1!

Murff

[Jmooney]

don't just turn off breakers at post - unplug -

[Filthy-Beast]

My 2cents: There is stray current on the frame, when you feel the tingle you are the path to ground. Check your ground connections at the CC box and also your ground connections to the frame. Then you can look for what is putting voltage out on the frame.

[notaz3]

Hook one end of a multimeter to frame, jam other end into the dirt / ground if voltage present you have problems. I had this happen ones and found that during assembly a screw had gone through one of the power wires electrifying the metal frame.

[TWP723]

Unplug that thing. Something is definately wrong. Our friends pop-up was so electrified, we couldn't even touch it. The CG power was the culprit. Usually is. Do you own an EMS?

[ALJO]

Clean the neutral (white) and the grounds on the frame close to the battery box and close to the power converter. All what the do at the factory is use a self tapping screw with a washer install the connectors to the painted frame (very poor connection) but that's the way it is. Clean the frame till it is bare and use some copper grease to reinstall the connectors.

[KYCAMPER]

All current entering your camper from the CG transformer must return to the CG transformer. Normally the path is through the neutral conductor. Since the neutral of the transformer is grounded to earth, the current can get back to the transformer through any other path to earth including through your wet hand. I don't know how campers are wired but it would be logical that the neutral and ground be separate back to the pedestal. I would unplug and check ohms between neutral and ground in the camper. Should be infinite. If ok then tell CG there is a problem with their ground. Apparently not a major problem with the ground since you are only getting a minor tingle but it could escalate to a more serious ground problem and someone in your camper could get electrocuted.

[JayTripperS]

We had a similar situation when we first purchased our 165 sport. I checked every receptacle and connection I could get to, only to find that the culprit was in fact the ground wire at the 30 amp plug at my house. We never used the outlet until we bought the camper.

[VicS1950]

As has been posted here already, any tingling or shocks at all are dangerous and potentially lethal.

Mike Sokol has done some great research and provided good reference as to understanding your system. He highlights some of the dangers involved with RV power systems.

Every RV owner should review his site.

The Shocking Truth About RVs | No~Shock~Zone

The comments and replies here about trailer shocks and system problems are exactly why I recommend using GFI protection if anyone installs a home 30 amp trailer receptacle. Just because the majority of campgrounds don't install them ($$) and the NEC National Electrical Code doesn't mandate them doesn't mean that they aren't a good safety device for RV's.

vlc

[wbarnes]

Here is update on some of the tests I did as a result of your respective comments. I will start with saying that I have very limited electrical knowledge, but will describe what I have done so far in hopes that you have suggestions on next steps.


1) I used a contactless tester to test for voltage on the frame in several spots (frame, stairs, the places I got the shocks, steel bumper, door frame, etc). The tester was silent suggesting no voltage detected. I also confirmed tester working by checking against an electrified outlet. So far so good.


2) I tested the CG power receptacle (again). Hot and Neutral = 122v, Hot and Ground = 122 volts, Neutral and Ground = 0 volts. Seems like the CG power is fine.


3) Same test as #2 except I did it at the end of the 30Amp Extension Power Cord I am using. Same voltage levels. Seems like the extension cord is fine.


4) I tested the CG power receptacle with one of the 3 prong Testers that indicate wiring faults. As the tester is a 15amp prong type, I connected it through a 15A to 30A adapter. The tester shows wiring is correct.


5) I pounded a copper pipe into the ground and tested voltage from the trailer frame to ground (copper pipe). I am receiving 6 to 7 volt reading. Uh oh??


6) I tested from the metal box that surrounds the CG power receptacle to ground (via copper pipe). It is showing same 6 to 7 volt reading. hmmm?


7) I did the same "Frame to Copper Pipe" test on other trailers adjacent to me. They are ranging from 3.5 volts to 7 volts; with most being around 6 volt range.


8) I did the same "Frame to Copper Pipe" test on another trailer that is in an older section of the campground further away from me. This trailer showed 0.7 volts.


9) I tested all the trailer 120v outlets inside/outside my trailer with the outlet tester. All outlets tested as correct wiring.


10) I disconnected CG Power and tested frame to ground (battery still hooked up). It gave me negative .5 volts. Not sure what this means or suggests.


11) I disconnected the battery from trailer and tested across the battery posts. It is showing 11.6 volts. So, battery is discharged (despite being charged by trailer for 3 days). Not sure if this can present the problem I am having or not. I don't think so based on my next test.


12) With battery disconnected; I reconnected CG power and did the "Frame to Copper Pipe" test. Still showing 6-7 volts.


13) Turned on all trailer devices that were on when I received the shock (Water Heater, Lights, Stereo, Bathroom Fan, Fridge. Voltages were changing up/down with each appliance being cycled on but overall, stayed in same area, approx. 5-7 volts.


14) I opened the junction box at front of trailer near hitch. There was 1 yellow wire that was capped with a marrette but not connected anything. This yellow wire comes from the whip that connects to tow vehicle. Although I didn't test these individual wires as I have no clue what they are; but nothing obvious in visual inspection that anything shorting out by touching perimeter of the junction box.


I have sent an email to campground owner to make him aware of my issue.


Anything further I should test. What do the results have you thinking it is likely to be? My interpretation of the results has me thinking it is the trailer and not the CG power; but this wouldn't explain why everyone in my area has same readings on their chassis (would be very unlikely that we al have electrical issues within our trailers).


Is the frame to copper pipe a valid test and what is the expected voltage range for this specific type test (if valid)?


Bill

[Jmooney]

How about the condition of the ground connection from negative side of the battery to trailer frame?

Also check output charging voltage from converter to battery cables ( charging voltage?)

I'm assuming that while doing all the afore listed testing that the " tingling " from the frame is now gone? Also out of curiosity, what type of ground did your body create when you felt this? ( standing on wet grass for example )

[ALJO]

The yellow wire is for the backup lights. Most TT's or 5er don't have backup lights.

[wbarnes]

How about the condition of the ground connection from negative side of the battery to trailer frame?

How would I test that? I presume by placing positive lead of meter on negative battery post and the negative lead on the frame?

I'm assuming that while doing all the afore listed testing that the " tingling " from the frame is now gone? A

Correct. It seems that it is only when hands are wet. I can freely touch frame with dry hands and feel nothing at all.

Also out of curiosity, what type of ground did your body create when you felt this? ( standing on wet grass for example )

In both cases, we were standing/kneeling on a couple inches of sand. For myself, I would have been in rubber soled sneakers; but my bare knee may or may not have been touching sand.

Thanks

Bill

[Jmooney]

from the battery. Follow the negative wire. It should be bolted to the trailer frame pretty close by. Make sure that is clean and tight.

There is a reason why your battery is not charged after 3 days. Either the cells are dry and the battery is dead, or you have a wire problem, or on the converter is not providing charging voltage ( fuse of bad converter )

[Jmooney]

The tingling you described may just be low DC voltage that you felt ( like putting a 9volt battery against your tongue )

I think we all thought you had some serious shock and thought you had a 110v issue. But your battery is dead, so something is still wrong. Maybe you blew a fuse to your battery. Usually one by the battery and one up in the converter power center