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Old 09-05-2012, 09:05 PM   #1
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Outlet contact with box changes test reading


This is baffling. All the outlets in the upstairs of this house test hot/neutral reverse. So I pull all of them out of the wall and check the wiring to find if they are all wired correctly, ie the black wire to the hot/brass side. They all look fine. I checked an outlet while it is hanging out of the box and suddenly it tests normal. The moment the outlet mounting screws touches the metal box the outlet again tests hot/neutral reverse. How can the mere contact with the box change the reading?

The other thing strange about the outlets in this room is that when I put a wand style electric tester within an inch of the outlet it starts to beep. Normally I have to insert it into the hot slot to make it beep. In this room the tester beeps by merely waving the wand anywhere near the whole box. What is going on here?

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Old 09-05-2012, 09:35 PM   #2
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Outlet contact with box changes test reading


You don't have a good ground connection there.

Try checking voltage between the "hot" and the "ground" using a solenoid-type loading voltage tester.

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Old 09-05-2012, 11:11 PM   #3
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Outlet contact with box changes test reading


kbsparky, this is an older house and has only ungrounded cable. The two downstairs bedrooms are on the same circuit, and obviusly the same ungorunded cable, but this only happens upstairs. I have tested all other outlets in the house and none of them test hot/neutral reversed and you have to put the wand all the way into the slot to get a reading of power for the downstairs outlets.
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Old 09-06-2012, 08:48 AM   #4
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Outlet contact with box changes test reading


I think if I replaced all the metal boxes with plastic it may make them test correctly, but what is the source of this problem?
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Old 09-06-2012, 10:50 AM   #5
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Outlet contact with box changes test reading


I have googled my situation, and apparently this has never happened to anyone else in the history of the world. I am stumped.
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Old 09-06-2012, 01:11 PM   #6
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Outlet contact with box changes test reading


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This is baffling. All the outlets in the upstairs of this house test hot/neutral reverse....... How can the mere contact with the box change the reading?
what made you start poking meter leads into the receptacles in the first place? Most people do not wake up one day and decide to go check their receptacles with a meter.
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Old 09-06-2012, 01:51 PM   #7
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Outlet contact with box changes test reading


This is a rental property that was inspected by a city inspector. All I have to do is make the outlet read open ground instead of hot/neutral reverse. Also I would like to fix this problem.
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Old 09-06-2012, 09:40 PM   #8
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Outlet contact with box changes test reading


My meter only has a 600 V setting. When I measure the balck and white power in wires it is 92.6. The two wires going downstream measure 18.4. I dont know why they measure anything. When I measure the power in black wire and the box it is 17.3. Power in white wire and box is 2.4.


Just to see what would happen I joined a ground wire to the box and the green screw on the outlet and the outlet then tested hot/neutral reveresed when it was in or out of the box. I guess that is consistent.
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Old 09-07-2012, 12:24 AM   #9
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Outlet contact with box changes test reading


It sounds like you actually have a hot-neutral reverse, and ungrounded metal boxes. Check voltage between a grounded metal object like a plumbing fixture and the receptacle.
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Old 09-07-2012, 08:59 AM   #10
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Outlet contact with box changes test reading


I checked all the outlets for hot/neutral reverse and they are all correctly wired. The two downstairs bedroom s also have metal boxes and read only ungrounded.
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Old 09-07-2012, 10:13 AM   #11
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Outlet contact with box changes test reading


Are you sure the tester is indicating a hot/neutral reverse, and not a hot/ground reverse? Those things are fickle when dealing with an open ground condition, and sometimes will indicate such when the ground is inductively picking up phantom voltage....

If you read the directions carefully, those testers will NOT properly indicate when more than one hot wire is present. This is the same condition.
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Old 09-07-2012, 10:19 AM   #12
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Outlet contact with box changes test reading


did you check at the box to make sure the hot/neutral is correct there? or at a junction box where that circuit leads to upstairs?
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Old 09-07-2012, 10:42 AM   #13
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Outlet contact with box changes test reading


Only the red and yellow lights come on indicating a hot/neutral reverse. There is no junction box leading to upstairs which does have me concerned. They may have just done it somewhere in the wall. I HOPE not. There are switches in the room which may be screwing this all up so I will check in those boxes to see if they were used as a junction. One pair of switches is a three way that governs lights from botom and top of stairs. These do not work right in that sometimes when the bottom switch turns off the light the top one cannot turn it back on. It does not always happen, but it is strange.


The main thing throwing me is why do the outlets test fine OUTSIDE of the box, but not INSIDE when the screws touch.

Last edited by crescere; 09-07-2012 at 10:46 AM.
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Old 09-07-2012, 01:59 PM   #14
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Outlet contact with box changes test reading


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I checked all the outlets for hot/neutral reverse and they are all correctly wired. The two downstairs bedroom s also have metal boxes and read only ungrounded.
You said you looked at the wire colors and they were correct. That's irrelevant. Measure the voltage between a known grounded reference and each terminal of the receptacle.
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Old 09-07-2012, 02:37 PM   #15
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Outlet contact with box changes test reading


Without a ground at the box there is no way to tell hot from neutral. Its a question of relativity. If you declare one ground then the other is 120VAC compared to it. With the ground pin floating it cannot reliably predict which is ground or neutral.

It sound like you have three prong recptacle where the ground pin is not connected. I think this is a no no. and implies safety that isn't present. You have to install 2 prong receptacle to signify there is no ground. If you want to go the extra mile put a GFCI in the first outlet of the run to afford some level of safety for the lack of a ground. If you want to be a great landlord run new 3 grounded wiring to all these outlets.

http://www.homedepot.com/buy/leviton...l#.UEpMhpbec7c

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