RV "Hot Skin" and GFCI?

The earth I stand on is the conductor I am joined to. Without entering an arena of idiotic semantics the only point of issue that I deal with when discussing "hot skin is "The other point of conduction, the earth my feet trod"

A bit of reality versus E=MC2
Owner of property I was renting in Mexico pshaw-ed my claim that he had a massive leak that caused a potential between the concrete stops set in earth and the earth the steps were set in. Meter showed a potentially lethal voltage of 122V.

I am going to make this hopefully crustal clear - the concrete steps were set atop earth. Neighbor children were complaining of getting severe shocks when going barefoot. Step onto the first concrete step and BZZZZZZT!

Being I had no screw in light bulbs handy I went to the hardware store and purchased a sixty watt incandescent lamp, base, and wire.

I brought the doubting property owner to the site. Stuck one stripped wire end into the ground then scratched the other bared wire tip across the concrete step.

The lamp flared to full brightness for a moment then dimmed. Remove step wire and wait. A second later another scratch across the step brought forth another flash of the bulb.

You can argue this point 'till the cows come home...

And not fix the problem...

I hired two laborers with promises of a case of beer to dig up the buried service entrance lead.

Tah...Dah!
Forty feet from the house there was a splice made in the entry lead. Two wires, twisted and taped. 2nd Tah...Dah. When wires were lifted from earth the shocks stopped.

YEAH! Why Oh why oh why oh why?

Didn't the electrical leakage simply jump from taped up line splice to taped up neutral splice. Six inches away? Oh tell me oh tell me oh tell me...

Well, it didn't and that's the important part isn't it? Sometimes things do not pencil out.
I re-spliced soldered then shrank tubing over the faults. End of problem.

By establishing a leak is current limited then shunting that leak to earth-tierra firma-ground the electrocution problem is resolved.

In the case of the OP's problem it means bonding the rig to earth, the stuff you plant seeds in. not trusting that somewhere else in the park a "bootstrap" ground has been made either by accident or negligence.

I bond Quicksilver to the earth whenever I am plugged into shore power. Being the recipient of a new pacemaker my concerns over this issue have been refreshed.

Isolation of the cause can be undertaken only after the EFFECTS have been neutralized.

Bear with my nagging - when I earth bond directly there are no issues nor can there ever be issues with Quicksilver ever getting a hot skin. Impossible. I stake my life on it.

I want to make sure I'm not masking a potentially worsening problem by either an electric ground or an earth ground.

Although I'm not totally confident of the GFCI on the pedestal, I plugged into it (with the ground intact) and ran a couple of loads. Nothing tripped.

Back on 50A (with ground intact), I measured current from the frame at 0.7mA.

I think introduced the open ground (30A) during which I measure just shy of 4mA current. Interestingly, the voltage (with the main breaker of the distribution center on) was back up to 57V. Random?

I think the GFCI is set to trip at 5mA so it would seem you are good to go.
Get that new PI board installed and quit playing with the open ground.

To measure power converter leakage to ground, power up the converter with no ground connections, either on the case or AC cord. Then simply measure the current between one side of the AC line and the converter ground connection, then repeat for the other side of the AC line. The measurement can vary with the load on the converter and the AC input voltage. As I mentioned earlier, it's hopefully pretty balanced to avoid GFCI trips. A legitimate reason for this leakage is RFI suppression. I guess it could be interesting to measure both AC and DC current. I'd expect no DC current.

(IF WE ASSUME YOUR POWER CORD GROUND HAS CONTINUITY?) My guess is that there is an OPEN NEUTRAL and maybe OPEN GROUND in the feed to the campsite box 20a/ GFCI circuit.
Because of the open Neutral/ and/ or Ground,
even water intrusion can cause problems BLEEDING voltage over to what should be grounded wires,
putting voltage on the skins, which (SHOULD BE)
GROUNDED THROUGH THOSE OPEN WIRES. You checked voltage, but did you check Neutral and Ground? (In YOUR Case) YOU are relying on the ground at the Pedestal, and it was missing?

tim.rohrer wrote:
Yesterday I discovered I had the troubling “hot skin” condition. After some troubleshooting and testing of different configurations, I determined I could only resolve the hot skin condition by physically disconnecting the RV power cord from the pedestal. Our cord is old and even the power input on the side of our RV shows wear so I purchased a brand new cord and power input.

Before connecting the new cord (I haven’t swapped out the power inputs), I used my multimeter to confirm the power at the pedestal was good. I then connected the new cord but did not energize the 50A circuit. The hot skin condition returned. Here is where it gets interesting.

I decided to test the 30A and 20A circuits at the pedestal using the multimeter; both circuits were off and I had not touched them since we arrived at this campground a few days ago. I flipped on the 30A breaker and tested voltages with the multimeter. No issues. I then flipped the 20A breaker and noted the GFCI plug was tripped. I reset it, and flipped the breaker. On a whim, I checked the RV and the hot skin condition was GONE. I have since tripped the GFCI and turned off the 20A breaker, but the hot skin condition has not returned.

So, especially for any electricians out there, what the heck happened? How could a pedestal be wired such that clearing a probably-blown GFCI (on a different circuit) could have led to this? And why didn’t the EMS system in my coach pick up the problem?

Thanks in advance.

Tim