Understanding GFCI outlets
Q. We just bought an old house, built in the 1950s, so the electrical outlets are not grounded. We'd like to add GFCI outlets near the bathroom and kitchen sinks for shock protection, but our home inspector told us that GFCI outlets will only work if there are ground wires. According to the inspector, GFCIs are useless without a ground. Is this true?
A. Ground fault circuit interrupters (GFCIs) do not have to be grounded to prevent electric shock. The belief that they need a ground is a common misbelief, even among some home inspectors and electricians.
For those who are unfamiliar with the term "GFCI," these are the outlets (commonly seen in bathroom) where there are two built-in buttons between the receptacles, often red and black. The lower button is for testing the GFCI. The top button is a reset switch. The purpose of a GFCI outlet is to prevent electric shock when using an electrical fixture in a wet location, such as near sinks, in garages or outside.
Since the term "ground fault circuit interrupter" includes the word "ground," it is often assumed a ground is needed for the GFCI to function. Here is why that is not true.
GFCI outlets contain a sensing device that can detect when the amperage (the flow of electrical current) in the hot and neutral wires of the circuit are not equal. When a circuit is uninterrupted (flowing properly), the hot and neutral have equal amperage. If some of the current is escaping from the circuit, as when a person is being shocked, the hot and neutral no longer have equal amperage. If the amount of escaping current is as little as 5 milliamperes (five one-thousandths of a single amp), the GFCI breaker trips, and electric shock or electrocution is prevented.
This works even when the GFCI is not connected to a ground wire. So go ahead and install those GFCI outlets in your bathrooms and kitchen, as well as garage and exterior outlets. They are also advised for outlets near laundry sinks, wet-bars, hot tubs and swimming pools.
Q. In one of your columns, you said a basement bedroom must have a window for fire escape. I am currently renting a basement bedroom. The window only opens 7 inches, which is too small for fire escape but, according to the local building inspector, the room meets code because it is equipped with a fire sprinkler. Do you agree with this exception?
A. The basement window requirement is a safety standard that applies in all cases, even when there are fire sprinklers. Suppose there were a fire in the aftermath of an earthquake or explosion. The water lines could be damaged, rendering the fire sprinklers inactive. Even if the sprinklers were working, does the building official expect a person to remain in a burning building while being sprayed with water?
You should submit this question to the head of the building department, instead of an inspector. In fact, rather than mention your particular situation, just ask whether a bedroom with fire sprinklers is required to have a window large enough for emergency escape.
• To write to Barry Stone, visit him on the web at www.housedetective.com, or write AMG, 1776 Jami Lee Court, Suite 218, San Luis Obispo, CA 94301.
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