Using outlet testers to trip a GFCI
Typically, when a home inspection happens, the inspector randomly test outlets that are protected by a GFCI outlet with an outlet tester. Outlet testers are fairly inexpensive tools that can tell us whether an outlet is wired correctly and has the ability to recreate a ground fault which should cause the GFCI to trip. The way an outlet tester creates a ground fault is by essentially touching the neutral and ground wires together which sends a message to the GFCI to trip and stop the flow of power to the outlets it’s protecting. When a ground wire is not present the outlet tester no longer can create a ground-fault event, so the GFCI isn’t signaled to trip. Although the outlet tester cannot create a ground-fault that does not mean the GFCI is not working correctly, it simply means that we’re not able to test the GFCI with an outlet tester. The GFCI’s electronics will detect an imbalance between the hot and neutral conductors when a true ground fault occurs and trip the GFCI outlet.
National Electrical Code decoded
Receptacles are just the technical names for outlets. A non-grounding-type receptacle would be a two-prong outlet. The third prong at the bottom of a plug is the ground, and before the ground wire was installed in homes, there were no three-prong plugs. It goes on to say that we’re able to replace two-prong outlets with three-prong outlets as long as it’s supplied by a ground-fault circuit interrupter (GFCI). Most of the time we’re able to replace the first outlet on the circuit with a GFCI outlet the same way that GFCI outlets protect bathroom circuits and kitchen circuits. The other option is to protect the circuit at the breaker by replacing the existing breaker with one that is a GFCI breaker. It’s common to see outlets in kitchens or bathrooms with a label on the plate that says “GFCI Protected” anytime an outlet that is not a GFCI is protected by one that outlet should be labeled with a small sticker letting you know that it is protected. It sums up the code by letting us know that while we’re installing three-prong outlets, we’re not required to rewire the circuit to include the ground wire. While we do need GFCI protection on the circuit we’re also not required to replace every outlet with a GFCI outlet, we certainly could, but it’s more cost than what’s needed.
Have a question about ungrounded outlets?
What the NEC says about ungrounded circuits
The 2017 National Electrical Code (NEC) 406.4 (D) (2) (c) states, “A non-grounding-type receptacle(s) shall be permitted to be replaced with a grounding-type receptacle(s) where supplied through a ground-fault circuit interrupter. Where grounding-type receptacles are supplied through the ground-fault circuit interrupter, grounding-type receptacles or their cover plates shall be marked “GFCI Protected” and “No Equipment Ground,” visible after installation. An equipment grounding conductor shall not be connected between the grounding-type receptacles.” I know that sounds like a bunch of electrical jargon, and it is but let’s break it down.
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What is GFCI protection?
A ground fault event is when an energized conductor comes into contact with the ground. A ground fault could happen if a plugged-in item fell into a bathtub where someone was bathing. GFCI protection is meant to stop electrocution by switching off the power to the item plugged in before electrocution occurs. By code, GFCI protection is required in areas where outlets could get wet like bathrooms, kitchens, laundry rooms, garages, and outdoors.
Homes built prior to the Vietnam war era were most likely wired with a two wire system, and two prong outlets were installed. They lack the extra safety feature of a ground wire to help better protect the home and wiring. The ground wire will help circuit breakers detect shorts and faults and trip when these events occur.
The only true way to ground the home is to rewire it by running a ground wire to each outlet, switch, and fixture. Rewiring sounds like a big undertaking, and that’s because it is, the sheetrock will need to either be cut into and patched or taken down. However, there is hope! Rewiring is not the only option.
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