Can a Surge Protector stop a hot-skin?
Just the basic today...
A post from the Rockwood RV Fan club…
Ok, for those who are sitting on the fence about buying one of these I want to tell you that it saved us on our trip. The first two campgrounds we stayed at the Watchdog detected an open ground at the pedestal which can be very catastrophic. For those of you who are on the fence about spending the money on a Watchdog it’s worth it. The expert in our group can explain in greater detail why.
Everyone,
Looks like I’m the expert, so here goes! 😁
I’ve been studying hot-skin voltage on a RV for 15 years and done dozens of formal experiments to understand it. And in my alternate life as a pro-sound engineer mixing concerts my interest in hot-chassis voltage goes back at least 40 years. So in that time I’ve developed a pretty solid understanding of what a hot-skin/chassis is, what causes it, how to troubleshoot it, and repair procedures. I’ll post the complete list of all my hot-skin articles tomorrow.
Just the basics today…
If you want to watch my 9-minute video on how Surge Protectors work, you can find it HERE.
And you can read just one of my articles on what a hot-skin voltage is HERE.
Yes, EMS/Advanced Surge Protectors will detect an open ground and shut off the power to your RV. They do this by measuring any voltage difference between the ground and neutral conductors in the pedestal receptacle. When that occurs there’s a big relay (called a contactor) inside of the unit that disconnects the line and neutral shore power connections. And in 99% of the cases that will disrupt the fault current path through your RV.
Are open grounds dangerous?
Yes, because any leakage current in your RV doesn’t have a path to ground, so it turns into a voltage that can shock you if you make contact with the skin (or chassis) of your RV while standing on the ground.
Not all Surge Protectors are the same
You need an EMS/Advanced Surge Protector from companies like Southwire Surge Guard, Progressive Industries or Hughes Watchdog. They cost around $300 to $400 and with different models can be hung on the pedestal or mounted inside of the RV.
Basic MOV surge protectors (on the left) cannot disconnect your RV from shore power that’s lost its ground connection. But they do protect your RV from voltage spikes due to nearby lightning strikes, etc.
EMS/Advanced (Total Electrical Protection) Surge Protectors (on the right) include MOV surge protection as well as monitoring power for high voltage, low voltage, reverse polarity and open-ground conditions.
See you tomorrow with the complete list of all my Surge Protector / Hot-Skin Articles.
Let’s play safe out there… Mike
An EMS can detect wiring issues at the pedestal, but not in the wiring in the RV itself. if the open ground occurs in the RV and there is a short from line ("hot") to chassis with enough resistance not to trip any of the circuit breakers, then the chassis can have dangerous voltages on it. In my opinion, a dual range non-contact voltage tester (such as the Klein Tools NCVT-2) is required to reliably detect hot skin. I believe an NCVT-2 and an EMS are the best defense against hot skin.
It should be stated that a surge protector can only protect us from open grounds that occur upstream from its location in our shore power circuit path. If the ground were to open somewhere downstream (such as in your shore power cable or connector) I believe it could not detect it. Mike, could you weigh in on this?