A GFCI cuts the power when it senses current leaking out of the circuit, such as through water or a person. Check for a wet connection first, then damage to the cord and whatever is plugged in. If it keeps tripping and you can’t find why, call an electrician.
What to check
A wet plug or connection
How to tell: Water on a plug, a cord connection or an outdoor outlet. A wet connector can let current escape from its live parts, and a leak like that is what a GFCI cuts the power for.
Fix: Don’t press RESET yet. With dry hands, unplug the extension cord from the wall outlet first, pulling on the plug, not at the wet connection. If the outlet or a connection is sitting in water, don’t touch it, and call an electrician. Let the plugs and connections dry before you plug back in and reset. Keep plugs and connections off the ground and dry, and use watertight or sealable connectors. Outdoors, use a cord made for outdoor use (see the letters on the cord).
Damage to the cord or what’s plugged in
How to tell: Frayed wires, cuts or cracks in the extension cord or an appliance’s cord, or a trip every time you plug in or turn on one thing. Ground faults most often come from damaged or defective equipment.
Fix: Unplug the damaged cord or the device that seems to cause the trip. Replace a damaged extension cord, and don’t use the device again until it’s repaired or replaced.
An extension cord too light for the load
How to tell: The cord’s gauge is lighter than what you’re running needs for that length. Ryobi’s pressure washer manual says an undersized cord can cause overheating, loss of power, and circuit breaker or GFCI tripping.
Fix: Use a heavier cord. See the extension cord gauge chart.
Several things on one GFCI, or a very long run
How to tell: It trips only when several things run at once. Small leaks from several tools can add up, and so can leaks along very long circuits.
Fix: Move some of the load to an outlet on a different GFCI.
For outdoor holiday lights, see indoor vs outdoor Christmas lights. For a pressure washer, check whether its plug has its own GFCI with TEST and RESET buttons, and see pressure washer extension cords.
Test the GFCI
Plug a lamp into the GFCI outlet and turn it on. Press TEST, and the lamp should go out. Press RESET, and it should come back on. Or follow the instructions that came with the GFCI. Test every GFCI at least once a month, and after a power failure.
A GFCI outlet also protects the outlets wired after it on the same circuit, so an outlet without TEST and RESET buttons can be protected by a GFCI outlet somewhere else.
When to call an electrician
- It keeps tripping, or the reason isn’t obvious.
- TEST doesn’t cut the power, or RESET doesn’t bring it back. Don’t use that outlet until it’s fixed.
- The outlet is discolored or warm, or plugs fit loosely in it. Stop using it until it’s replaced.
- An outdoor outlet you need to use has no GFCI protection. Until it’s fixed, a portable GFCI or an extension cord with a GFCI built in adds protection where you plug in.
Don’t bypass a GFCI, or move to an outlet without one, to stop the trips. A GFCI is there to protect you from a severe shock.