What is a Ground Fault Circuit Interrupter?
According to the National Electrical Code, in all kitchens, bathrooms, garages, or any area in which water may be present, instead of regular receptacles (outlets), GFI receptacles should be used. These are for your safety.
The idea of a GFI receptacle is that if there is the slightest electrical problem, the GFI immediately shuts off the power. This is an important safety feature.
When you lose power to a receptacle in a kitchen, bathroom, garage, or outdoor area, check to see if it's a GFI receptacle. If it is, press the “TEST” button, then press the “RESET” button. If the GFI shuts off power repeatedly, plug in a different appliance to test whether the problem is the first appliance or the GFI itself. If the GFI is defective, call a good electrician.
Hint: You may have a receptacle that has lost power in a kitchen, bathroom, garage, or outdoor area but it's not a GFI. It may be “protected” by a GFI that has tripped off somewhere else. You can check for this situation by making sure that all the GFIs in your kitchen, bathroom, garage, and outdoor areas are working properly.
More Technical Data About GFIs
A GFI receptacle (also called a GFCI receptacle) can measure differences in power as small as 3ma (which is a very small amount). When it detects more power coming in from the "hot" side than going out from the neutral side, it will shut off. This is a good thing because that extra electricity has to go somewhere, and it's important to protect you and your family from it.
All GFI receptacles should be tested monthly. This is done by pressing the "TEST" button. If pressing the "TEST" button does not make the button labeled "RESET" pop out, then call an electrician. If the "RESET" button does pop out, the outlet is OK. Press the "RESET" button back in to reset the outlet.