Frequently Asked Questions About Ground Fault Circuit Interrupters

Ground fault circuit interruptors (GFCIs) first saw use in the 1970s. Since then, they have saved thousands of lives from accidental electrocution.

What is the purpose of GFCIs?

The purpose of GFCIs is to prevent a ground fault, an unintentional electrical path between a power source and a grounded surface. This is most likely to occur when an electrical appliance comes into contact with water. When electrical parts become wet, they cause electrical current to flow outside of the circuit conductors. If you are in contact with the wet surface and the electrical appliance you could be severely shocked, or even electrocuted. For this reason, GFCIs are mostly installed in kitchens, bathrooms and outdoors.

How do GFCIs work?

GFCIs work by instantly interrupting power to the circuit if the electricity flowing into the circuit differs by even a small amount from that returning, indicating a loss of current.

Can I install GFCIs myself?

While GFCIs are relatively cheap and readily available in building supply stores, they should only be installed by a licensed electrician.

How do I know my GFCIs are working?

Test your GFCIs once a month by doing the following.

1. Push the “reset” button in on the GFCI.

2. Plug a light into the GFCI and turn it ON. The light should now be on.

3. Push the “test” button of the GFCI. The light should turn OFF.

4. Push the “reset” button again. The light should now go ON again.

If the light does not turn off when the “test” button is pushed, the GFCI is not working properly and it should be serviced by a licensed electrician.

Have questions about GFCIs or other electrical systems? Call ABC Plumbing, Sewer, Heating, Cooling and Electric, we're here to help.