UL Issues Advice on Ground Fault Circuit Interrupters
RECENT testing by Underwriters Laboratories (UL) of samples obtained from both the marketplace and several manufacturers indicates that some ground fault circuit interrupter (GFCI) units do not meet all current UL requirements and, under rare conditions, may not trip when a fault is present, resulting in a loss of protection from electric shock.
There have been no reported incidences of these products causing injury in the field, and under normal circumstances UL expects these products will perform their intended function. While GFCIs provide an effective means for protecting against electric shock, UL recommends that they be tested regularly to verify they are operating properly, using the self-test feature that is built into these devices. UL encourages users to test and monitor their GFCIs using the process described below.
UL has notified all manufacturers identified to date whose product samples did not meet all current UL requirements so that they may take appropriate action. UL has not withdrawn its certification mark from existing products nor does UL believe the products should be removed from homes or other locations entailing normal use.
UL may issue further advice as additional testing is conducted and its review proceeds.
Name of Product: Wall receptacle-type Ground Fault Circuit Interrupter (GFCI). Rated 15 or 20 Amps, 125 volts.
Advisory: Under rare conditions, these GFCIs may not trip when a fault is present and may malfunction resulting in a loss of protection from electric shock. There have been no reported incidences of the products causing injury in the field.
Identification: Ground Fault Circuit Interrupters look like duplex receptacles but are distinguished by their "Reset" and "Test" buttons.
Uninstalled Product: All affected manufacturers identified to date have been notified. Retailers, contractors and electricians should contact the manufacturer for further information.
Installed GFCIs: If the GFCI is already installed in your home, UL recommends that all GFCIs be tested monthly following these steps:
- Push the "Reset" button located on the GFCI receptacle first to assure normal GFCI operation.
- Plug a product (such as a lamp) into the GFCI receptacle and turn the product "ON."
- Push the "Test" button located on the GFCI receptacle. The lamp or other appliance should go "OFF."
- Push the "Reset" button, again. The lamp or other appliance should go "ON" again.
- Repeat this test with the lamp or other appliance plugged into a receptacle marked "GFCI Protected" in close proximity to the GFCI receptacle. Push the "Test" button again and the lamp should go off.
In addition to the monthly test, UL recommends that GFCIs installed in environments with both sustained high temperatures (greater than 90 degrees Fahrenheit) and high humidity (greater than 93 percent relative humidity) be tested with greater frequency. These environments may include some bathrooms and indoor pool areas.
UL recommends that the GFCI be replaced by a qualified electrician if:
- The lamp or other appliance plugged into the GFCI remains "ON" when the "Test" button is pushed.
- The GFCI does not reset when the "Reset" button is pushed.
- The GFCI performs its intended function, but trips repeatedly during normal use. This may indicate either a faulty appliance or a compromised GFCI. In either case, replacement of the GFCI is recommended and the appliance should be checked for proper operation prior to reuse.
Finally, with all GFCIs, it is important that consumers not use the unit's "Test" and "Reset" buttons as an on-off switch for appliances plugged in to the GFCI.
Consumers are urged to continue to use GFCIs, as they play an important role in protecting you and your homes. If your GFCIs require replacement, UL recommends that a qualified electrician does the replacement.