09/13/2018
I'm often contacted regarding an issue with a GFCI (Ground Fault Circuit Interupter) receptacle, or sometimes referred to as a GFI. The complaint is usually related to the receptacle tripping. I'll usually stop by the residence or business to take a look at the situation, depending on the information given over the phone.
Many times I realize that the person doesn't actually understand how the receptacle is designed to function and the purpose of the receptacle.
GFCI receptacles are designed to protect people from a short to ground on, or within, the device that is being plugged into it. Usually you'll find the receptacle located in places where there's a potential for water to be present, such as kitchens, bathrooms, garages, and outside locations.
An example of it's function is a toaster that is plugged into the receptacle on your kitchen counter-top. The toaster is getting old and has been used a lot. Over time there might be a heating element that is starting to go bad. As this element goes bad it becomes faulty, with the possibilty of shocking the person who comes in contact with the frame of the toaster. When it starts to "fault to ground" it trips the GFCI receptacle instead of electrocuting a person.
The GFCI is an important safety device that is required by code in specific locations. GFCI devices came into existance in the 60's and have gradually been improved functionally. The devices internal electronics can wear out with age. As they get older they can start to "trip out" without a ground fault event, causing "nuisance tripping". That's usually an indication that it's time to install a new one. More often than not it's the thing that's plugged into the GFI that's starting to malfunction, not the receptacle itself.
Another comment I get about GFCI's is someone thinking that they plugged "too many" things into the receptacle and they think it's tripping because it's "overloaded" (too much current). The GCFI isn't designed to trip when there's too much current being drawn through the device. That isn't how it works. It's only designed to measure the current drawn through the "hot" wire (usually black) and compare that current to the current being returned through the neutral wire. If there's an imbalance of these two current measurements it assumes that the difference in current is going to ground and the receptacle trips.
A GFCI receptacle can, and does, protect other receptacles that are located "downstream" of it. Usually, whether in the kitchen, garage, or outside, the first receptacle in the circuit is a GFCI receptacle and the rest of the receptacles on that circuit are normal receptacles and are protected by that GFCI receptacle for similar faults to ground. If you find that a receptacle somewhere doesn't have power check to make sure your GFCI's aren't tripped, removing power from additional receptacles downstream.
If you need help regarding your GFCI receptacles, or any receptacles, that don't seem to be functioning properly I'd be happy to stop by, or talk with you by phone, and see if there's a solution to your problem.
Scott Ross
