A GFI, or GFCI – Ground Fault Circuit Interupter device protects us from receiving electric shocks from faults in the electrical devices we use in our home. It works by comparing the input current on the hot side to the output current on the neutral side. If there’s the slightest difference in current, on the order of a few milliamps, then there is current leaking out somewhere, possibly through somebody’s body. To protect us in this situation, the device very quickly cuts off the power supply to the leaking device, within 20-30 milliseconds, greatly reducing any possible human tissue damage from errant current.
A GFCI can also prevent fires from short circuits and other electrical faults that don’t involve humans such as a low current short where the current never reaches the trigger point for a circuit breaker , e.g. a live wire falls in a tub of water or moist soil and only 1 or 2 amps of current flows.
GFCI outlets are important, especially when the electrical outlets are positioned close to water. Installing GFCI outlets in your kitchen, bathrooms, laundry rooms, pool house etc., is a good idea. Apart from being an essential preventive measure, the law also requires you to have GFCI outlets installed throughout your home. According to National Electric Code (NEC), all homes must be equipped with GFCI protection. Initially, it was only required for you to install GFCI outlets near water but this requirement has been extended to cover all single phase outlets of 125 volts in recent years. GFCI outlets should also be installed on temporary wiring systems during construction, renovation or maintenance of structures that are using power temporarily.
