Safe - and properly grounded - at home

Tag : Home Electrical Appliances

Q: I was hoping you guys could tell your readers what the benefitswould be in installing GFCI outlets even if there is no groundingwire. There are probably many homeowners who would be willing toinstall GFCIs themselves but who aren't able to install a groundingwire or are unwilling to pay a electrician to install one. Ipurchased a package of three that came with little stickers to puton the outlet if it is not grounded.
Maybe you could suggest the best locations to install them(bathroom, by kitchen sink, by laundry tub).

A: Great suggestion. The benefit is summed up in one word: safety.
Ground fault circuit interrupters (GFCIs) are essential to a saferesidential electrical system, especially an older one. At one timeor another every owner of an older home has pondered why theirreceptacles have two prongs when most appliances are equipped withthree-pronged plugs. Back in our "rookie" days we used our fairshare of plug adapters to make the SkilSaw run from a two-prongedoutlet. Luckily, we didn't get fried.
Look at a modern 120-volt outlet. There are two vertical slots anda round hole centered below them. The left slot is slightly largerthan the right. The left slot is the "neutral," the right slot isthe "hot" and the hole below them is the "ground."
Behind the scenes, a black wire is connected to the hot hole, and awhite wire is connected to the neutral hole. A non-insulated wireis connected to a green screw that is connected to the ground. Theground slot and the neutral slot of an outlet are identical. In thecircuit panel you'll find that the neutral and ground wires fromall of the outlets go to the same place, the ground.
Electricity flows from the hot side of the distribution panelthrough the "hot" wire through plugs and switches to the neutralwire and back to the neutral side of the panel.
Plug in an appliance and power is diverted from the plug to thedevice, allowing electricity to flow through the device to run amotor, heat some coils or light a lamp.
Circuit breakers in the distribution panel protect the electricalsystem from overload and possible fire. If a circuit breakerdetects a short in the system, for example when a hot wire touchesa neutral wire, it cuts off the flow of electricity. The circuitbreaker prevents the wires in the wall or the outlet itself fromoverheating and starting a fire.
Think of a GFCI as a mini-circuit breaker. It protects againstelectrical shock. An unintentional electric path between a sourceof current and a grounded surface is a "ground fault." Hence thename ground fault circuit interrupter. Ground faults occur whencurrent is leaking. In effect, it's electricity escaping to theground. If your body provides the path to the ground, you could beburned, severely shocked or killed.
Two examples of accidents underscore that hazard. According to theConsumer Product Safety Commission:
-- Two children, ages 5 and 6, were electrocuted in Texas when aplugged-in hair dryer fell into the tub in which they were bathing.
-- A 3-year-old Kansas girl was electrocuted when she touched afaulty countertop.
GFCIs are a good idea on an older, ungrounded system because a GFCIreceptacle is not dependent on an independent ground wire tofunction because it does not measure shorts to ground. Rather, aGFCI monitors the amount of current flowing from the hot leg to theneutral leg of the receptacle. If there is any imbalance, thecircuit is tripped.
A GFCI is able to sense a mismatch as small as 4 or 5 milliamps,and it can react as quickly as one-thirtieth of a second, shuttingthe circuit off. So a ground fault circuit interrupter is acritical layer of protection in areas where it's likely thatelectricity can come into contact with water or other ungroundedconductors.
GFCIs are easy to install for someone with a basic knowledge ofelectrical wiring. They install much like a regular receptacle withthe hot wire (black) attached to the brass screw on the receptacleand the neutral wire (white) attached to the silver screw.
Make sure to turn off the power to the receptacle before taking theplate off. GFCI protection is required for most outdoorreceptacles, bathroom receptacle circuits, garage wall outlets,kitchen receptacles and all receptacles in crawl spaces andunfinished basements. This can be accomplished by installing a GFCIcircuit breaker on these circuits or installing a GFCI receptacleat the first outlet downstream from the distribution panel. Thiswill protect all receptacles downstream.
Finally, GFCI receptacles should be tested monthly. Plug anightlight or lamp into the outlet. The light should be on. Then,press the "test" button on the GFCI. The GFCI's "reset" buttonshould pop out, and the light should go out. If the reset buttonpops out but the light does not go out, the GFCI has beenimproperly wired. If the reset button does not pop out, the GFCI isdefective and should be replaced. If the GFCI is functioningproperly, and the lamp goes out, press the reset button to restorepower to the outlet.