Here’s a comment/question from last week’s article “What’s All This Electrical ‘Ground’ Stuff About?“
Dear Mike,
I have a major concern. We host at a popular state park that has allowed some conditions to develop at several sites that allows water to stand after a rain that covers the pad and extends to around the power pedestal for a depth of several inches. The result is a camper is an island with their power cord in the water and going up to the electric plugs. This can last for 6-10 hours after a rain of only an inch or so. Park staff knows about this as the condition has existed for several years. My thought is that this is totally not safe. Park staff responds that it will drain and dry up. How best to address this? —Michael F.
Dear Michael,
I’m sure you’ve heard that famous adage “Electricity and water don’t mix.” And they’re completely right! Situations that might be safe on dry land can become extremely hazardous when you add water. Your particular situation is a prime example of two dangerous but different scenarios. Let’s take a look at the two major ways that this can turn deadly in an instant.
Scenario #1: Extension cord laying in the water created electrified puddle
If you have a shore power cord that’s rated for immersion in water (yes, they do make them for the marine industry), and if there are no cuts or cracks in the insulation, and there are no power plugs actually in the water, and there’s been no attempted repair such as electrical tape on an insulation break, then MAYBE it might be safe (as long as scenario #2 below doesn’t occur). That’s because the jacket insulation would prevent the electrical conductors from touching the water in the puddle.
However, if ANY of the above conditions exist, then your power cord in the water would effectively electrify the puddle for perhaps dozens of feet in all directions. So someone stepping in that electrified puddle and touching anything else grounded (the RV door handle in the next campsite, perhaps?) could receive a serious shock that might be deadly. And under the right conditions you wouldn’t even need to touch anything else. Just the voltage gradient in the water can be enough to cause you to lose control of your muscles and possibly die.
For example, last year in Washington, D.C., a mother and her son were electrocuted in their basement when the sump pump developed a broken wire and it electrified the water. When they walked down the steps to see why the pump wasn’t working, they were killed from the electric current going through the water without even touching the pump. There was no GFCI powering the outlet as required by code, which would have saved their lives.Â
Scenario #2: Hot-Skin RV in the water creates shock hazard
Now let’s assume that your shore power cord and all connections are perfect – no breaks in the insulation and no submerged plugs. But what if there’s a loss of the ground wire somewhere in the power distribution system? Maybe the pedestal has lost its ground through corrosion or a break in the wire. Or perhaps the chassis-bond has failed inside of your RV’s circuit breaker panel. If that occurs, there’s nothing to direct any fault currents in your RV’s electrical system to a safe path. So now your entire RV can be electrified to 120 volts with a hot skin condition.
If that occurred and someone walked up to your RV door on dry dirt, they might only feel a tingle and be warned about the hazard. But standing in a puddle of water while touching your RV’s electrified steps or door handle would be dangerous and possibly deadly. This happened to a teenager in Muncie, Indiana, a few years ago. The power outlet in the shed feeding the RV in the back yard developed a broken ground, and the teen walked barefoot across the wet grass in the middle of the night. When he put one foot on the metal steps with his other foot still in the wet grass, he was killed.Â
What To Do About This?
If you’re actually a host at this campground, then you could potentially assume some of the liability if someone were shocked or killed. And this goes all the way up to the campground owners (the state), as well as the managers in between. So I would tell the campground managers in no uncertain terms that what they’re doing is dangerous and could cause a death.
I would also suggest you report the situation to your local electrical inspector. Even though the campground has gotten away with it for years without anyone getting injured, it only takes the right set of circumstances to cause an electrocution … and nobody wants that to happen.
Let’s play safe out there….
Mike Sokol is an electrical and professional sound expert with 40 years in the industry. Visit NoShockZone.org for more electrical safety tips. His excellent book RV Electrical Safety is available at Amazon.com. For more info on Mike’s qualifications as an electrical expert, click here.
##RVT827
Shocks occur from a difference of potential if the surface of the ground is a better conductor than the ground connection of the system you may be shocked. In electrical substation you can find a buried grid under the ground to help dissipate this difference of potential, RV parks do not have these and most have sub panels for power which keeps the ground and neutral separated thus more chance for the difference. All of this is just like the bird on the wire as long as there is no difference of potential there will be no shock.
While we mostly boondock, on occasion we stay in RV parks. When we plug in, some parks have a ‘door’ you pull up and plug in. Others have had just a plug with NO door to pull up. I’ve always wondered if the plugs with no doors would present a problem if it should start raining. Couldn’t rain water come between the plug and my connection – and short out?
No, rain won’t provide enough conductivity in this instance to short it out. That would require something really conductive across the contacts themselves. So a nail or piece of wire falling across the terminals would create a short and trip the circuit breaker. That small amount of water would probably present only a small leakage current of a few mA, which won’t do anything significant. However, I do worry about corrosion on the contacts. And that can eventually cause overheating and loss of power.
Hi Mike
I read your articles diligently and usually have to read twice to grasp concepts. (accountant by trade). Question: In charging my 12 volt , 24MDP, 625 MCA battery, while in storage, is it better to charge/maintain with a Battery Tender or plug 120 volt shore power into my RV electrical inlet?
thanks
ken
I would say that disconnecting your battery and hooking it to a battery tender might be the better choice, but check to see if your RV’s inverter/charger has a battery tender function built in. Many of them do already, so if it does that might be a good choice as well. What brand and model inverter/charger do you have?