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Tester says ground and hot are reversed -- doesn't look it

Tester says ground and hot are reversed -- doesn't look it


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Old 06-26-18, 12:56 PM
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Tester says ground and hot are reversed -- doesn't look it

My electric socket tester shows that the hot and ground are reversed in a bedroom outlet. However, when I pulled the outlet from the wall, the hot wire was where it should be and the ground to the green screw. Any ideas what's wrong? Should I try installing a new outlet?
 
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Old 06-26-18, 12:59 PM
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That happens when the wires get crossed at an upstream outlet. It can take some time poking around to find where they goofed up.
 
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Old 06-26-18, 01:01 PM
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Do you have a multimeter? If so, I would suggest that you measure the outlet voltage using your multimeter. Set it to AC Volts, and a scale that is higher than 120V. Here's what you should expect to measure if the outlet is wired correctly:

Hot to Neutral: 120VAC
Hot to Ground: 120VAC
Ground to Neutral: 0VAC
 
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Old 06-26-18, 01:07 PM
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Originally Posted by Astuff View Post
That happens when the wires get crossed at an upstream outlet. It can take some time poking around to find where they goofed up.
If the wires were crossed at an upstream outlet, wouldn't one of the other outlets show a fault also? None of the others in the house seemed to be wired incorrectly. Just trying to find a way to figure this out.
 
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Old 06-26-18, 01:18 PM
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It could happen if the wires are hooked up incorrectly from the upstream outlet in the circuit. If you plug the tester into the preceding outlet it could show correct because the incorrect wires are not providing power to that outlet.
 
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Old 06-26-18, 01:49 PM
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Those testers are nice toys but can easily give incorrect readings. You need an analog (not digital) multimeter to get a true reading. Follow Bob's guide to expected readings in post #3.
 
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Old 06-26-18, 09:52 PM
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Has anyone heard of a switch reversing polarity of outlet up the line. box has hot in hot out and switch leg. Out has correct polarity with switch off turn it on polarity swaps and burn up router. If i unhook switch leg at the light i have correct polarity. No junctions between switch and light. Is this an inadicate ground in the temp service
 
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Old 06-27-18, 08:33 AM
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R- Could be a MWBC with floating neutral.
 
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Old 06-27-18, 10:44 AM
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My electric socket tester shows that the hot and ground are reversed in a bedroom outlet. However, when I pulled the outlet from the wall, the hot wire was where it should be and the ground to the green screw. Any ideas what's wrong?

I think when you get a multimeter and test all wires you'll find you have an open neutral. Those plug-in testers leave a lot to be desired as far as accuracy, but are quick and easy. That's why building inspectors rely on them.
 
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Old 06-27-18, 11:13 AM
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I am from the old school. Connect a 120 volt bulb between a radiator in the room and first one wire then the other. The wire bulb lights on is 120 volt hot.
 
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Old 06-28-18, 07:31 AM
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Hot/Ground reverse signal on a bug style tester is almost always actually an open/broken neutral. The plug in tester can't tell the difference.

Hot/ground reverse can't happen without some seriously screwed up dangerous wiring. Open neutral happens all the time from normal wear and tear of electrical devices. Much more likely outcome.
 
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Old 07-02-18, 09:17 PM
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Brand new wire no junction this is a home run box. I have an old panel feeding new panel temporary with 8-3 under a 40a breaker. New panel runs whole house except 220s. Original ground is #10 200a feeders
 
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Old 07-03-18, 12:21 PM
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Brand new wire no junction this is a home run box. I have an old panel feeding new panel temporary with 8-3 under a 40a breaker. New panel runs whole house except 220s. Original ground is #10 200a feeders
How is this related to this thread and the original poster? Did you have a question?
 
 

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