Ground and hot skin, if I understand what I’ve read hot skin requires two things: a current leak to chassis/ground/skin and an improper or missing ground.
I’m trying to reconcile the above with a condition I ran into a campground. Underneath a TT roll up against the axle, I’m covered in sweat, ground is damp and I feel an electric tingle. Start to try to find the problem when a neighbor walks over and says every RV in the area has a low level of hot skin. Shoved one probe of the voltmeter in the dirt and touched the frame with the other probe. Did this on five or six RVs all showed 10 to 12 volts.
Another potential topic for discussion would be cord winders. They have brushes. In a prior motorhome, I experienced neutral failures in 2 of its cord winders resulting in damage to a TV, a satellite receiver and the ATS. The insulation on the neutral wire from the winder got charred. After the cord winder was removed, there were no more electrical problems. The wonders were replaced under warranty but the shop blamed the failures on power durges although an external surge protector was always used and the winder was never rotated after plugging into the pedestal.
Mike, thanks for another good article. A couple questions. As far as I know if you run a sub panel to an external building (like my barn) you need to have a ground rod but you leave the neutral/ground un bonded. Why wouldn't a pedestal which is basically a sub panel at an external building also require a ground rod? Is there any problems or dangers if every pedestal at a camp ground had ground rods? Would the extra ground rods hide problems like the other comment here with the hot skin?
One interesting thing you didn’t show in your Po Co diagram are the fuses. I know they have them, at least my power pole does because I’ve heard them blow and it sounds like a very loud gunshot. I assume they protect the transformer but I’m not sure. My Po Co just installed some kind of a safety device they said was to protect the fuses, but they didn’t say how it worked. I’m in a rural area with lots of trees which have a bad habit of dropping limbs which find their way onto power lines during wind and snow storms. Mike, do you know how the fusing works at the power pole/ transformer?
We are at a well maintained campground which recently upgraded all the campground electrical including pedestals. My neighbor had an issue with his hw and was trying to figure out, I was helping him with checking for power to hw tank and with my ncv realized he had a hot skin situation. We went through the breakers and found the circuit which I told him to leave off until fixed. I gave him this newsletter info to subscribe to. He got an electrician in next day and everything checked out on the rv and he traced the problem to the pedestal, ground issue. The electrician checked the ground at the main distribution panel and ended up putting a ground in at the pedestal which resolved the issue. Seems this has happened to other pedestals here as well.
The rv owner had no idea of the dangers of hot skin, neither did Park officials. So 2 things, thank you for sharing your expertise, I read all your emails and have gained valuable knowledge and you have gained another subscriber. Second is adding the ground to the pedestal seems to have fixed the situation but is it the proper fix.
Ground and hot skin, if I understand what I’ve read hot skin requires two things: a current leak to chassis/ground/skin and an improper or missing ground.
I’m trying to reconcile the above with a condition I ran into a campground. Underneath a TT roll up against the axle, I’m covered in sweat, ground is damp and I feel an electric tingle. Start to try to find the problem when a neighbor walks over and says every RV in the area has a low level of hot skin. Shoved one probe of the voltmeter in the dirt and touched the frame with the other probe. Did this on five or six RVs all showed 10 to 12 volts.
Any thoughts?
It could be a reflected hot-skin voltage. Read this: https://open.substack.com/pub/rvelectricity/p/whats-a-reflected-hot-skin-voltage?r=1txmtl&utm_campaign=post&utm_medium=web&showWelcomeOnShare=false
Another potential topic for discussion would be cord winders. They have brushes. In a prior motorhome, I experienced neutral failures in 2 of its cord winders resulting in damage to a TV, a satellite receiver and the ATS. The insulation on the neutral wire from the winder got charred. After the cord winder was removed, there were no more electrical problems. The wonders were replaced under warranty but the shop blamed the failures on power durges although an external surge protector was always used and the winder was never rotated after plugging into the pedestal.
Mike, thanks for another good article. A couple questions. As far as I know if you run a sub panel to an external building (like my barn) you need to have a ground rod but you leave the neutral/ground un bonded. Why wouldn't a pedestal which is basically a sub panel at an external building also require a ground rod? Is there any problems or dangers if every pedestal at a camp ground had ground rods? Would the extra ground rods hide problems like the other comment here with the hot skin?
One interesting thing you didn’t show in your Po Co diagram are the fuses. I know they have them, at least my power pole does because I’ve heard them blow and it sounds like a very loud gunshot. I assume they protect the transformer but I’m not sure. My Po Co just installed some kind of a safety device they said was to protect the fuses, but they didn’t say how it worked. I’m in a rural area with lots of trees which have a bad habit of dropping limbs which find their way onto power lines during wind and snow storms. Mike, do you know how the fusing works at the power pole/ transformer?
Hi Mike,
We are at a well maintained campground which recently upgraded all the campground electrical including pedestals. My neighbor had an issue with his hw and was trying to figure out, I was helping him with checking for power to hw tank and with my ncv realized he had a hot skin situation. We went through the breakers and found the circuit which I told him to leave off until fixed. I gave him this newsletter info to subscribe to. He got an electrician in next day and everything checked out on the rv and he traced the problem to the pedestal, ground issue. The electrician checked the ground at the main distribution panel and ended up putting a ground in at the pedestal which resolved the issue. Seems this has happened to other pedestals here as well.
The rv owner had no idea of the dangers of hot skin, neither did Park officials. So 2 things, thank you for sharing your expertise, I read all your emails and have gained valuable knowledge and you have gained another subscriber. Second is adding the ground to the pedestal seems to have fixed the situation but is it the proper fix.
Thanks
Allan
al_cardinal@live.com