Editor’s Note: The following report by Mike Sokol, a seasoned technology writer who has written hundreds of No~Shock~Zone and RV electricity articles for the RV industry over the last 10 years, examines the use of GFCIs on RVs in campgrounds. The article appeared in Sokol’s monthly RV Electricity newsletter and, more recently, on RVtravel.com. For more info.go to [email protected].
I received a number of inquiries last week about possible changes to the 2020 National Electrical Code (NEC) and how it might affect campgrounds and RVs that plug into their shore power.
Let me explain why I believe this could cause harm to you and other RVers.
For those of you who aren’t aware, the National Electrical Code has a three-year update cycle, with hundreds of electricians, engineers, inspectors and manufacturers involved in improving the safety and performance of the electrical systems that power our lives. And electrical power systems are vastly safer now than when I first started playing with electricity back in the mid-1960s.
Not only are grounding and bonding required for nearly everything, there have been huge technology advances in the last 20 years that have reduced shock hazards greatly. The best example of this would be GFCI that works by detecting small leakage currents to ground (5 mA or less, which is 0.005 amperes of current).
So, GFCIs have been required by code on all bathroom, kitchen and outdoor 15- and 20-amp outlets for the last few decades, and in that position they work very well. That’s because they’re protecting a single branch circuit with perhaps a few appliances connected to the same GFCI. And because of the code implementation, I do believe that GFCIs have saved a lot of lives, since their main job is protect humans from leakage currents.
Note that a GFCI is not a circuit breaker (even though it can be incorporated INTO a circuit breaker if desired), so it’s not there to protect wiring from too much current. No, it’s there to protect you from a shock of 5 mA to 100 mA of fault current that can go through your heart, causing ventricular fibrillation and death within minutes.
So GFCI protection has been required on the 20-amp pedestal outlets for quite a while, which I also believe is a good thing. However, someone on the 2020 revision code panel got the idea that if a GFCI outlet on a 20-amp branch circuit was a good idea, then requiring them on 30- and 50-amp pedestal outlets would be even better.
I have anecdotal evidence to back up my theory that total ground leakage currents in an RV shore power connection can easily total more than 5 mA. That’s because everything you plug into your RV leaks a little current to ground. That includes your microwave, stove, battery charger, inverters, air conditioner and control systems.
Most of these leakages are allowed by UL and the NEC, but each one could easily be 0.5 mA or so, with switching power supplies for your 12-volt converter having an exception to allow up to 3 mA of leakage (or thereabouts). Even long extension cords can create leakage currents through inductive coupling of their internal conductors. These leakage currents are additive, so you can see that just plugging in your normal electrical devices in an RV can easily add up to more than 5 mA of leakage current which is the threshold that will trip a GFCI. That means that GFCI protection on 20-amp circuits works quite well, but that’s probably not the case if they’re installed upstream on the 30- and 50-amp feeder circuits.
So here’s the big reason this is a bad idea. If the NEC code were to be fully implemented, I believe there would be lots of random GFCI tripping on the 30- and 50-amp breakers in campgrounds. The first time a camper comes back from a day trip and finds his air conditioner shut down and his or her pet suffering in the heat, or their refrigerator off with a bunch of spoiled food, they will figure out a way around the 30/50-amp GFCI tripping problem.
To view the full story click here. https://www.rvtravel.com/30-and-50-amp-gfcis-in-campgrounds/