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Joined: Aug 2002
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Recent inspection of a 15amp wall receptacle in an old house showed reefer to be ungrounded with tic tracer. Plug in tester showed wiring ok for recept. Futher look inside (knob & tube wiring) had jumper from neutral to ground screw. Why was tester showing ok receptacle & was reefer energized?
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Joined: Aug 2001
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The simple plug-in testers with three lights cannot detect every possible problem. They just have the three lights wired across each possible combination of hot, neutral, and ground. i.e. H-N, H-G, N-G. At a correctly wired receptacle both neutral and ground will be at (or very near to) ground potential, leaving the H-N and H-G lights illuminated. Connecting the receptacle ground to the neutral results in the same voltages at the outlet, so the tester indicates "All O.K." You'll notice that the guide to the light combinations on these testers has "Hot-Neutral reversed" and "Hot-ground reversed," but no "Neutral-Ground reversed." That's because they can't detect such an error.
The case of the appliance wouldn't have been energized so long as all connections remained sound. If the neutral ever opened somewhere along the circuit however, then the ground pin on the receptacle would rise to 120V taking the casing with it.
Far too much reliance is placed on these cheap testers.
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Joined: Mar 2001
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As I mentioned in another thread this practice can and does lead to electric shock.
There are plug in testers that will detect these sort of jack leg techniques but they cost about three hundred dollars. Those testers are becomming more popular with home inspecters and they do provide a lot of information.
--
Tom
Tom Horne
"This alternating current stuff is just a fad. It is much too dangerous for general use" Thomas Alva Edison
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Joined: May 2002
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Tom, could you provide information, ie the manufacturer of these analyzers?
Roger
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Joined: Jan 2002
Posts: 163
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I think he might be referring to: Sure Test (Branch Circuit Analyzers)...they make a number of models starting at about $300. I think I've seen these at different sites (IAEI?) Industrial Commercial Electronics, Inc. Tonawanda, NY (716) 692-2000 www.iceind.com
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Joined: Mar 2001
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The sure test is indeed one model of these testers.
--
Tom
Tom Horne
"This alternating current stuff is just a fad. It is much too dangerous for general use" Thomas Alva Edison
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Joined: Feb 2002
Posts: 2,233
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There was another tester called "THE INSPECTOR" and I am not sure who made it, but it did a lot of tests like, voltage drop, open circuits, open gounds, open neutrals, etc. that you would find on a three prong GFI tester.
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Joined: Jun 2001
Posts: 642
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The TASCO inspector II Try this as a link www.tasco-usa.com I saw this used by some inspectors in Kansas. Some of the inspectors swore by it - othhers swore at it. It's advertised price is $319.00.
ed
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