How Do GFCI Buttons Work?

A GFCI circuit constantly monitors the current in a circuit to protect humans from electrical shock. The colored buttons on the GFCI receptacle allow you to test how the receptacle is functioning.

How a GFCI Works

A GFCI monitors and makes certain that the current leaving, through the black wire, and coming back, through the white wire, are both equal. The GFCI will trip the circuit if it detects that the current coming back is less than the current leaving.

Using the Buttons

One button of the GFCI is normally marked "TEST." Pushing this button will shift some of the current from the black wire to the white wire. If a light, clock radio or other electrical device is plugged into the outlet, pushing the "TEST" button should shut off the power to the device. The "RESET" button should also pop out. Pressing the RESET button restores the power to the electrical device.

When to Check the Buttons

Pushing the "TEST" button on a monthly basis helps monitor whether the GFCI outlet is functioning properly. Make certain that the lamp, clock or other device plugged into the outlet goes out and the "RESET" button pops out.