GFCI's are smart sensing electric devices designed to "trip" in as little as 1/40 of a second when the intended path of electricity is diverted, namely to a person. These simple devices are an integral part of your home's electrical system, are easy to install, and save lives by limiting the duration of an electrical fault. However, my experience has shown me they are frequently installed incorrectly. Many a handyman or homeowner understands what a GFCI reset outlet is and how to reset it, but is not aware of the need to have the device properly installed and located at the most upstream outlet on that particular circuit.
Understand, properly installed GFI's can be a breaker at the electrical panel with a red reset button located on the breaker, or an electrical outlet with a red/black/white reset button at the most upstream location (1st outlet on the circuit). Post-construction installation may prove faulty though in some configurations without the proper detection equipment. Hence, the reason we always recommend trade licensed or certified technicians make repairs.
Here's an example of a GFI electrical misconfiguration I found recently which emphasizes the need for licensed electrician. The electrical panel was located within the interior of the garage and contained a GFI breaker with reset button. The automatic garage door opener and the two baths in the house were wired into that same GFI circuit. When testing/tripping the bath circuit, we quickly learned the GFI reset was at the garage electrical panel. The home did not have a personnel entrance to the garge other than the garage door itself. With the GFI circuit tripped, the automatic garage door opener would cease to function. As such, we were unable to access the electrical panel to reset the breaker! The bath outlet reset buttons were useless because they were not the most upstream outlets on the circuit and were totally unnecessary. GFI protection was still being provided at the bath outlets, but installation was incorrect because a 'trip' would disable the garage door. If the garage door was in the closed position, there was no way to get to the electrical panel. All this could've been avoided had the automatic garage door opener not been wired into a GFI circuit.
In short, GFI's are a great safety invention if installed properly. Remember, GFI's are required at any outlet within 6 feet of water. Currently, this means Kitchens, Baths, Laundry, Basements, Garages, Fountains, etc. Also, it's okay to have non-GFI outlets at these locations as long as their clearly designated as such.
Oh, you're probably wondering, "How did they ever get the garage door open to reset the breaker?" Reply to this blog and I'll be glad to share the secret.