Flipping Hot- Testing GFCI’s and unusual conditions
As home inspectors I find that we often see some conditions that many in a specific trade may not. Recently during a home inspection a truly odd one happened.
As I was tripping an exterior GFCI protected receptacles, as I have done hundreds and hundreds of times. I trip the device using a 3-bulb tester with a built in GFCI test circuit. When the device tripped if gave me a “Hot-Ground Reversed” reading. What!!!
Now these 3-bulb testers can give some erroneous readings time for time so I reset it and tripped the GFCI Device again and I get the same result, even when I trip it right at the GFCI receptacle.
So I now go get my Fluke T-Pro Wiggy/Solenoid style tester. To verify what I see.
With the device tripped I have no power from Hot to Neutral. This is what you would expect to see.
So with the device still tripped my Fluke T-Pro meter shows that I get 122 v neutral to the cover plate/ground. Well, this is not what you want to see.
Sure enough when the device is tripped it now is shunting power to the ground away from the hot conductor. Truly odd and potentially dangerous.
So now I go to the device itself and start to repeat the test. With the device reset I have no power from neutral to ground as we would expect.
Now I trip the device with the test button.
And as what you should see no power hot to neutral.
With the device still tripped I show 122 v neutral to ground… yikes.
So when I tested with the device tripped I get; Hot to Neutral – no voltage, Hot to ground 120v, Neutral to ground 120v… um never seen this before.
My client happens to have a neighbor who is an electrical contractor and he comes to see what the heck is going on. I think he thought I was being crazy (which may not be wrong).
So the electrician proceeds to test the device it and gets the same result. He looks at me and says “how did you come to look for this condition?” I explained exactly what I did and how I found the condition. He replaces the GFCI and then looks at me and says “good catch.”
He tells me he has never seen this before, I let him know this was a first for me also.
This is a great reminder to test these devices from time to time, and maybe testing other than what is considered the standard test method by just testing the device button. This condition would not have not been discovered if it were not for my little Dumb 3-Bulb tester.
If you find any errors or have additional information that would expand on any code, building standards or manufacturer requirements please let me know.
NCW Home Inspections, LLC is a Licensed Washington State Home Inspection service located in Wenatchee Washington serving Chelan County, Douglas County, Kittitas County, Okanogan County and Grant County Washington and the cities of Wenatchee, Leavenworth, Cashmere, Oroville, Cle Elum, East Wenatchee, Quincy and many more…
Your Wenatchee and Chelan Professional Real Estate, Home and Structural Pest Inspection Service
Coordinator & Instructor- Fundamentals of Home Inspection- Bellingham Technical College
Former WA Home Inspector Advisory Licensing Board
www.ncwhomeinspections.com 509-670-9572
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