Troubleshooting GFI Wiring

GFI wiring is one of the most basic safety measures installed in any home. GFI, also known as GFCI, stands for Ground Fault Circuit Interrupters. GFIs are outlets that prevent against electric shock. These are usually installed in areas where there are chances of electrical shock hazards like bathrooms, outdoor outlets, kitchens, basements and garages. 

How does GFI work?

There is a sensor inside the GFI that can detect changes in current to an appliance by comparing the current flowing to the appliance and the current flowing from the appliance. A potential drop off in the current will result in the GFI cutting off all the power by starting a relay which takes less than a second to trip. So, even before you can feel the shock, the power is cut off. Once the power to an appliance is cut off, it needs to be unplugged and the GFI needs to be reset.

Types of GFI

• Receptacle – Basic GFI outlet installed in the place of older outlets.
• Circuit breaker – Installed in a panel box in the circuit breaker, it is used to give protection to selected circuits. It can shut down electricity in-case of a short circuit or overload.
• Portable – Portable GFCI may be used where a GFI is not available nearby like in a lawn or a terrace. These are much more expensive than both Receptacles and Circuit breakers.

General Troubleshooting

• If a particular breaker is not working, turn it off and on again. If it doesn't work, replace it.
• If more than one breaker is not working, reset all breakers followed by all GFIs. If it doesn't help, try to locate a bad connection by checking and testing those at the interface between the non-working breakers and those that are functional.
• You can also try and replace the breaker and check the neutral connection at the panel. If two or more circuits are affected, make sure that main and sub-main breakers are not blocking the voltage.
• If the 6GFI or breaker re-trips after resetting, switch off everything on that circuit and try resetting again. Try doing it with sub main breakers until you find out which one is faulty.

GFI Troubleshooting

• All GFIs have 2 buttons related to testing labeled TEST and RESET.
• Turn on an appliance connected to GFI and press the TEST button. The appliance should immediate turn off.
• If the appliance does not switch off, there is something wrong with GFI wiring, the circuit or the GFI itself, in which case it should be replaced.
• Pressing the RESET button should restore the power to the appliance or circuit.

To troubleshoot a GFI, use a GFI tester, available at most hardware stores. The GFI tester is plugged into the GFI outlet and it gives you a snapshot of your connection, including wiring malfunctions and the condition of the GFI. An alternate and more extreme way to troubleshoot is to simply buy a new GFI and install it. GFI testers however, aren't very expensive and if you invest in one, it will probably come in handy every now and then.