According to the Consumer Protection Safety Commission (CPSC), a ground fault circuit interrupter (GFCI) outlet constantly monitors current flowing through a circuit. If the current flowing into the circuit differs by a very small amount (as little as 0.006 amperes) from the returning current, the GFCI interrupts power faster than a blink of an eye to prevent a lethal dose of electricity. GFCls are designed to operate before the electricity can affect your heartbeat. A GFCI works even on two-slot receptacles.
Per the CPSC, the National Electrical Code (NEC) requires GFCI-protected outlets for any outdoor use, bathrooms, and kitchens.
GFCI not intended for storage facilities
GFCI protection can also be at the circuit breaker. That created an issue in a storage facility at our office. The local building inspector now requires a GFCI circuit breaker be installed in any new or remodeled storage facility. This created an issue when a 2014 Winnebago View with a 30-amp service was plugged into a dedicated 50-amp plug for storage. Read the article here.
I contacted Mike Sokol, as he is “THE” expert on everything electrical. He stated that he helps develop the code. He explained it is not intended for storage facilities, and especially ones that have vehicles with multiple appliances. That is because there are voltage “leaks” that are acceptable but will trip a GFCI. As with many enforcement issues, it’s left to the interpretation of the local enforcement agency.
Code sometimes vague regarding GFCI outlet locations
I had a similar issue in my home with a kitchen outlet tripping randomly at the circuit breaker. I called my local electrician that had installed the panel during construction. He stated that they had this issue quite often and recommended replacing the GFCI circuit breaker with a standard one. “Is that legal?” I asked. “Or, better yet, is it safe?”
He told me that the code is a little too vague as it lists kitchen in general or anything within 6’ of a water source. The outlets on my kitchen countertop are used for a coffee pot, air fryer, and occasionally a toaster, but never at the same time. He also indicated there were a few appliances that should not be plugged into a GFCI outlet.
Microwave oven
The component that generates microwave energy is called a Magnetron. The initial surge at startup or cycle modes during defrost are very high and can trip the GFCI, as it senses a leak in voltage. Most microwave ovens in residential applications are direct wired to the circuit breaker. However, I have found many RV units that have a “ganged” outlet, with one being the main GFCI. The microwave oven in your RV should at least be a dedicated circuit.
Another issue is when RVers purchase a countertop microwave and plug it into the GFCI outlet on the back wall. This is called a “nuisance tripping.” The appliance is operating in a safe manner, but the GFCI is too sensitive for the surges and motor outputs and requires constant resetting.
Refrigerators
With the shift away from absorption refrigerators to residential or 12-volt models, the same issue occurs with power surges, especially with a residential model. Not only do these “cycle” during the day, causing compressor inrush, some also feature a defrost mode that comes on with a high power demand and ultimately a voltage leak.
Medical equipment/CPAP machine
More RVers are using medical devices for sleeping and even normal breathing such as CPAP machines and oxygen concentrations. Once again, these devices cycle during the day and night and create slight electrical surges. A GFCI cannot determine if it is actual normal operation or a dangerous leakage. These machines should be on a dedicated, non-GFCI outlet or circuit, and never used near a water source.
What should you do
Take a moment to identify what type of outlet these devices are plugged into. Keep in mind that not all GFCI-protected outlets have the test and reset button. Most manufacturers have one outlet with the test and reset button and others are just ganged with what we called “dummy plugs”. They had a GFCI sticker on the face when new, but that never seems to stay on.
And if you are getting a nuisance tripping from your air pot, or coffee maker, it might not be the appliance, but rather a very sensitive GFCI outlet.
You might also enjoy these posts from Dave
- Why does toaster oven trip the GFCI in RV bathroom?
- Can I use a 2-prong plug in a 3-prong outlet?
- Why does converter take 5-10 minutes to start charging? How to test it
- Follow-up on delayed converter charging and tripping GFCI issue
- All GFCI outlets work; why did 4 on other side quit working?
DAVE HAS ANSWERED MORE THAN 1,000 readers’ maintenance and repair questions. Read a directory here. There is so much to learn!
Dave Solberg is a leading expert in the RV industry and the author of the “RV Handbook.”
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RVDT2901
Our long-stay winter RV park allows small storage sheds. The only AC power source on the sites are the power pedestals – and typically on the opposite side of the RV from the shed.
I wired our little shed with an interior LED light strip and a switch box with a single 15A outlet, the exterior has a weatherproof box with an identical combo switch/outlet and a external LED light above the grill. I cut a 14ga (15A) outdoor power cord for the wiring inside the shed. There is a 15A male jack on the shed exterior that lets me power the shed with another 15A outdoor power cord to the GFIC protected outlet on that side of the RV (15A breaker inside the RV).