Ground Fault Circuit Interrupters (GFCI)

Since the 1970s, ground fault circuit interrupters (GFCIs) have saved thousands of lives and have helped cut the number of home electrocutions in half.


GFCIs are electrical safety devices that trip electrical circuits when they detect ground faults or leakage currents. A person who becomes part of a path for leakage current will be severely shocked or electrocuted. These outlets prevent deadly shock by quickly shutting off power to the circuit if the electricity flowing into the circuit differs by even a slight amount from that returning.
A GFCI should be used in any indoor or outdoor area where water may come into contact with electrical products. The National Electrical Code currently requires that GFCIs be used in all kitchens, bathrooms, garages, and outdoors. 
Testing Your GFCI
GFCIs should be tested once a month to make sure they are working properly.  
To test your GFCI:
  1. Push the “reset” button on the GFCI to prepare the outlet for testing.
  2. Plug in an ordinary nightlight into the GFCI and turn it ON. The light should now be on.
  3. Push the “test” button of the GFCI. The nightlight should turn OFF.
  4. Push the “reset” button again. The nightlight should now go ON again.
If the nightlight does not turn off when the “test button is pushed, then the GFCI may have been improperly wired or damaged and it does not offer shock protection. Contact a licensed electrician to check the GFCI and correct the problem.
The How to Test a GFCI fact sheet provides illustrated instructions.
Portable GFCI
While most GFCIs are outlets, a portable GFCI requires no special knowledge or equipment to install. One type is simply an extension cord combined with a GFCI. It adds flexibility in using receptacles that are not protected by GFCIs. Portable GFCIs should only be used on a temporary basis and should be tested prior to every use.
Find out more about GFCIs by viewing the GFCI Virtual Demonstration and reviewing the Q&A: Ground Fault Circuit Interrupters fact sheet.