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#81557 - 08/28/02 07:44 AM Jumper from neutral to ground screw
WGroll Offline
Junior Member

Registered: 08/28/02
Posts: 1
Loc: Annapolis, MD
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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#81558 - 08/28/02 01:24 PM Re: Jumper from neutral to ground screw
pauluk Offline
Member

Registered: 08/11/01
Posts: 7693
Loc: Norfolk, England
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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#81559 - 09/01/02 11:17 AM Re: Jumper from neutral to ground screw
tdhorne Offline
Member

Registered: 03/22/01
Posts: 344
Loc: Maryland, USA
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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#81560 - 09/02/02 05:45 PM Re: Jumper from neutral to ground screw
Roger Offline
Member

Registered: 05/18/02
Posts: 1779
Loc: N.C.
Tom, could you provide information, ie the manufacturer of these analyzers?

Roger

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#81561 - 09/03/02 10:41 PM Re: Jumper from neutral to ground screw
dana1028 Offline
Member

Registered: 01/09/02
Posts: 163
Loc: San Carlos, CA
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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#81562 - 09/04/02 08:46 AM Re: Jumper from neutral to ground screw
tdhorne Offline
Member

Registered: 03/22/01
Posts: 344
Loc: Maryland, USA
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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#81563 - 09/05/02 05:47 PM Re: Jumper from neutral to ground screw
harold endean Offline
Member

Registered: 02/16/02
Posts: 2248
Loc: Boonton, NJ
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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#81564 - 09/05/02 09:07 PM Re: Jumper from neutral to ground screw
nesparky Offline
Member

Registered: 06/21/01
Posts: 650
Loc: omaha,ne
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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