GFCIs: Important Safety Feature… IF They’re Working

This is the start of a series of blogs on safety information.  This article is on lightning and GFCIs – an important safety feature in your home if they’re working.

Lightning, Florida, and the Potential Impact on Your GFCIs

Florida is the “lightning capital” in the U.S. with thunderstorms occurring, on average, about 100 days each year.  More specifically, the area between Lake Okeechobee (to the south) and St. Augustine (to the north) and between the east and west coasts of Florida is the area of highest risk for a lightning strike.*  Vero Beach is situated within this area.

Fun fact:  Java, an island in Indonesia, is the “lightning capital” of the world with an average of 223 thunderstorm days each year.*

Although lightning is, itself, electricity, it can wreak havoc on your electrical service and connected electronics.  I will discuss electronics in another blog, but this blog concerns GFCIs.  As a quick review from my earlier blog, GFCI stands for ground fault circuit interrupter and these devices constantly measure the flow of electricity through the two wires that form a closed circuit.  The flow of electricity must be the same on both wires, within 4 – 6 milliamps (4 to 6 one thousands of an amp).  When the current is not the same in both wires the GFCI device opens (or “trips”) in less than 1/10 of a second significantly reducing the danger of an electrical shock.

Research: Percentage of GFCIs Not Functioning Properly

In short, you want your GFCIs to be fully operational to avoid an unpleasant shock (or worse).  A 1999 study by the American Society of Home Inspectors found the failure rate on GFCIs to be over 50% in southwest Florida.   In the rest of the country they found 19% of the 4,585 GFCI receptacles, and 21% of the 1,583 GFCI circuit breakers, did not provide electrical shock protection.**

The results of this study caused concern with NEMA – the National Electrical Manufacturers Association – who commissioned their own study.  As the name of the association implies, many manufacturers of GFCI receptacles and circuit breakers are members of NEMA.  Not surprisingly, this study showed a much lower percentage of GFCI receptacle failure, but still a significant 10% in the lightning sub-group (Tampa – where 19 of 190 GFCI receptacles failed).***

Whether the actual percentage of failed GFCI receptacles is 10% or 50%, it is prudent to do a regular check (monthly is recommended) to ensure your GFCIs are working.  Lightning strikes can certainly render this device useless.  And, like any manufactured equipment, GFCIs do have a service life.  The length of the service life depends upon multiple factors including:

• Manufacturer quality of the device
• How often the device is used (are hair dryers and electric toothbrushes plugged and unplugged multiple times per day?)
• Level and duration of humidity

A reasonable service life for a good GFCI device is 10 – 15 years, but lower quality devices may be as few as 3 – 5 years.  So it makes sense to test your GFCI receptacles on a regular basis.

Regular Testing of Your GFCI is a Safety Essential

Testing your GFCI receptacles is quite easy.  You need the device to both “trip” – meaning power to the outlet is cut – and to reset:

1. 1. To test a GFCI press the button on the face of the outlet that says “test”.  You will hear a click that trips the outlet and cuts the power.  When you plug in your electric razor, or night light, it won’t function.  That’s a good thing and it means your GFCI is working.  If yo

ur razor or night light still work, then the GFCI receptacle needs to be replaced because it is no longer functioning.

1. Next press the “reset” button.  You should be able to push the reset button in and have it stay in place.  If your reset button goes in, but doesn’t stay in, then the GFCI receptacle needs to be replaced.

The good news is that automatic, self-testing GFCIs are available now and will become required by the National Electrical Code in the future.  The self-testing GFCIs will automatically cut power to the outlet when the device is no longer operational and can provide an audible alarm to alert you that the outlet power has been turned off.

As always, feel free to contact me if you have any questions at ThisOldElectrician@yahoo.com or 772-473-5245.

* “When Lightning Strikes”
** “Are All Those GFCIs Out There Working?”, November/December 1999 IAEI News
*** “NEMA GFCI Field Test Survey Report”, January 2001.