All inspector tools have their limitations.
Sometimes inspectors must rely on several different tools to provide the best information about a particular condition. Today I want to talk about the limitations of one very common tool that inspectors “rely” on—-and why perhaps they should not. The tool is the $9.99 (give or take), three-bulb, receptacle tester.
If the inspector relies only on this tool for their evaluation of the electrical receptacles (sometimes mistakenly referred to as “outlets”) in the home, they will not likely find some defects. One such defect is the “False Ground” or commonly called, “Bootleg Ground.”
Unlike any of Bob Dylan’s Bootleg albums—this one can cause you harm.
At a recent inspection, the home had all “three-prong” type receptacles. Some were properly wired while many others had ‘False Grounds.” One is most likely to find false grounds in older two-wire circuits—-where there is no ground wire.
“Handy” homeowners will sometimes tackle replacement of these receptacles. The homeowner sees the nice green grounding screw and thinks something has to be connected to it. They further surmises that since the ground wires and neutral wires are all connected together in the main service panel anyway—-why not just connect the neutral wire to the ground-screw and call it good. Surely if they are connected together in the panel they must do the same job. (of course they for sure do not do the same job and they are connected together in the main panel for an entirely different reason.) Sure enough the receptacle tests as “Correct” with their handy-dandy three-bulb tester—adding to their confidence that they must have wired it correctly. (This “repair” of course, gets rid of the old “deal-killer” two-prong receptacles as well.)
IT DOES NOT HOWEVER PROVIDE “ACTUAL” GROUNDING OF THE RECEPTACLE. If actual grounding is important to the device that is plugged into the receptacle, “actual” grounding would not be there. Grounding provides a path to ground for current if it becomes necessary. If you look closely at the following picture you can see that there is a piece of wire connecting the white neutral screw location to the green ground screw location.
So to find this defect (and other defects that the $9.99 tester can’t find) the Inspector needs the $299.99 (give or take) tester in their bag of tricks.
There are a couple of defects that this expensive tester can only “indicate” by a “blank” or “flashing” screen. But if we have used our $19.99 (give or take) Voltage Indicator we know there is “voltage” there—-so even though the screen is blank, we know there is “something” wrong . At that point we might want to take out our old fashioned two cable circuit tester to figure things out.
The $9.99 tester will also tell us these “blank-screen” defects: a “disconnected neutral” or the “hot connected to the ground wire terminal.”
So, I think you can see that relying on just one piece of electrical testing equipment could result in not telling the whole story about electrical issues within the home—and possibly even telling the wrong information about electrical issues within the home.
Charles Buell, Real Estate Inspections in Seattle
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