By Lon Grossman
What exactly are GFCI’s and what do they do?
GFCI’s have been around for many years. They are inexpensive devices that prevent electrocution. They are, in essence, little microprocessors that monitor the flow of electricity going across them. If they detect the slightest imbalance within three to five milliamps
(.003-.005 amperes) it shuts the circuit down. For those of you counting, that’s a lot quicker than a heartbeat.
Electricity flows in a circuit. The current in the black wire should equal the current in the white wire. Any imbalance means there is a fault somewhere, and that’s not good. Without a GFCI, someone coming in contact with that situation by touching an appliance or light fixture could be electrocuted. End of story. With a properly wired and working GFCI, there should be no problem with the exception of the electrician’s bill, which in this case, is not expensive.
The previous paragraph holds the key to this story. In 2000, the Leviton Corp. joined forces with the American Society of Home Inspectors (ASHI). The alliance was to do a GFCI survey at existing properties. The inspectors turned in their results of more than 13,000 home and buillding inspections and found that 15 percent of GFCI’s were not working properly. In areas that have a lot of lightning strikes, the percentage of failures jumped to between 23 and 58 percent.
The lightning did not have to strike the house to cause a failure. The surge alone can damage the GFCI’s. More problematic is that when a GFCI fails, you usually still have electricity flowing. The failure means it no longer offers ground fault protection. Read that as you could get burned, severly shocked or electrocuted.
How do you know if your GFCI receptacle is properly working? First, because they are mechanical devices, they can wear out or corrode. Once a month, every GFCI should be tested. The least a homeowner should do is the monthly maintenance. Plug an ordinary night light into th GFCI and turn it on. Push the “test” button on the GFCI. The nighlight should go off. Push the “reset” button on the receptacle to reset it and the night light should come back on. If the light did not turn off, the GFCI is not working, or it is wired improperly. In either case, it will not provide shock protection and should be replaced or checked by a license electrician, but this can also give the occupant a false positive. The more complete test should be performed with a tool designed to specifically test for a secondary problem that could exist.
This tool is inexpensive and called a GFCI Circuit Tester. GFCI testers are available for under 15 dollars at hardware, big box stores and electrical supply outlets. Most home inspectors use them to test an outlet’s wiring and to test a GFCI by creating a current imbalance when the tester’s button is pushed. The important point to remember is to test, and reset those GFCI’s every month.
Life-saving GFCI’s were first required by the National Electrical Code in 1971 for outdoor receptacles and any outlet within 15 feet of a swimming pool. In 1975, bathroom receptacles were included in the code and in 1978, the NEC added garages. Kitchen outlets within six feet of the sink, were added in 1987. They included all unfinished basement and crawl space outlets in 1996.
Because of their great track record for saving lives, GFCI’s became code for all kitchen counter top outlets and bathrooms. All exterior receptacles (including sheds) were added to the code 1996.
There are basically three types of GFCI’s. One is the receptacle type that many of us have in our kitchen and bathrooms, which have two buttons in them that state in fine print “test monthly”. One button is stamped “test” and the other “reset”.
Another type is located in the electrical service box and is a GFCI/circuit breaker combination. The third is an extension cord type with a built-in GFCI protector that is perfect when using tools and lawn equipment.
But remember. To have them installed by a licensed electrician and test/inspect them every month. They are there to save you life. Don’t fail them.
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