This Phoenix home inspection video tip explains the importance of GFCI (Ground Fault Circuit Interrupter) outlets, which are sometimes called GFI (Ground Fault Interrupter) circuits. GFCI devices are critically important for preventing electrical shock. The NEC (National Electrical Code) requires the use of GFCI protected circuits in situations where electrical shock is a strong possibility. This includes all outlets in baths, garages, crawl spaces, kitchens and utility rooms near sinks, and all outdoor outlets. These are areas where contact with water could occur.
How a GFCI Works
A GFCI measures the current on the live side of the circuit and compares it to current returning on the neutral side. When they are not equal, that means something is causing the current to leak to ground. This is what occurs when someone is in contact with water and receives an electrical shock. it also occurs when there is an electrical short somewhere in the circuit. When this occurs, the GFCI acts like a circuit breaker and shuts off the power. The shutoff happens very fast, which should prevent a fatal electrical shock. GFCI’s have a reset button that must be pressed to reset the device after the problem is resolved.
Each outlet does not require a separate GFCI device. Outlets are chained together in parallel (called a circuit), so only the first outlet in the chain requires the GFCI. The GFCI will protect all the other outlets further in circuit. There will typically be one GFCI outlet per bathroom. Depending upon the size of a kitchen and the number of electrical circuits, there may be more than one. Each GFCI protects one electrical circuit. The protection only occurs at the GFCI outlet and any outlets further down the line in the electrical circuit.
There are two basic types of GFCI devices. One is built into an outlet and the other is built into a circuit breaker found in an electrical breaker panel. If you run any wiring underground outside of the home, electrical codes may require the use of a GFCI circuit breaker in the electrical panel. If you are not sure about whether or not you need to add a GFCI to a circuit, call your local city electrical inspector.
The National Electrical Code started to require GFCI circuits as far back as 1971. If you remodel an older home, you may be required to upgrade the electrical circuits to include these protective devices.
Never replace a GFCI outlet with a standard outlet. If the GFCI outlet appears to be kicking off on its own, either there is a problem with the electrical circuit that needs to be resolved, or the GFCI outlet needs replacement. The GFCI is there to protect you from electrocution, so it should never be removed (except for replacement) or bypassed.