Non-Contact Voltage Tester Use


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Old 12-31-22, 01:29 PM
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Non-Contact Voltage Tester Use

I bought a Non-Contact Voltage Tester, ADWSET AE22, and have a question reference using it.

I have outside flood lights that do not come on when the switch is turned to ON. I have a line from a circuit breaker box to a 2-gang box. The 2-gang box has 2 switches in it. One switch controls the overhead in the shop and the other switch controls the outside flood lights. The overhead light works as normal when turned off/on. The outside flood lights do not work when turned on. I checked and there is power to the flood lights switch and the switch works as I put in a new one and tested it just in case old one was bad with no change.. I went into the attic and when the switch is off to either the overhead lights or the flood lights their respective lines provide no reading/sound on the Non-Contact Voltage Tester. When I turn on both light switches the line that runs from the switch to the overhead lights when using the Non-Contact Voltage Tester beeps what I'd call normal...beep...beep...beep. But when I use the Non-Contact Voltage Tester on the line running from the switch to the outside flood lights the Non-Contact Voltage Tester has a rapid beeping. This would tell me I'm getting power but there is a problem. What would cause this? I've checked all the bulbs and they work. Suggestions?
 
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Old 12-31-22, 01:51 PM
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Welcome to the forums.

A non contact tester has one sole purpose.
It's to tell you that there is hazardous voltage in the area or box.
So you could have hot/120v to the floodlights but be missing the neutral wire.

The non contact tester cannot test for open neutral.
 
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Old 12-31-22, 01:53 PM
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Non-contact voltage testers are only good for a quick check to see if there MIGHT be hazardous voltage present. They are not good for real troubleshooting as they often give false positives. In order to troubleshoot your issue you need a simple volt meter that can read voltage and continuity which most meters do. Any meter will do but a simple analog meter is often better for a novice to use.

Your issue could be an open neutral wire which a non-contact tester will not detect.
 
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Old 12-31-22, 03:26 PM
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Thanks for the feedback. I did put a volt meter on the switch and 120v is passing through. They've worked since 2004 when I wired it then. Just recently this problem came up. I'll go back in the attic and check any junction boxes in case something came loose over the years. I just had never used a Non-Contact Voltage Tester before and thus the question.
 
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Old 12-31-22, 05:02 PM
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Reading 120VAC across the switch terminals shows the switch contacts are OPEN. Flip the switch and the 120V should disappear (switch contacts CLOSED). If it doesn't disappear, the switch is bad.
 
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Old 12-31-22, 07:48 PM
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If you check each switch terminal to neutral or ground and you get 120 volts then the switch is good and you need to check elsewhere in the circuit. The next place I would check would be at the fixture.

Use the meter probes and check for 120 volts at the socket. If you have 120 volts between the screw shell and the middle tab then the light should work. If not, it is time to remove the fixture and check the connections there. Keep working your way back to the switch box until you find the issue.
 
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Old 01-02-23, 02:38 PM
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I checked the junction boxes in the attic and found where I had 4 wires coming together in one box and one of the Neutral wires had come loose. Corrected with larger wire connector and all works well. Amazing how a wire comes loose after being good for 10 years. But suspect heat/cold can make a difference. Thanks for the replies.
 
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Old 01-02-23, 03:56 PM
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Glad to hear you found the issue.
I like to twist the wires together so I am not relying on the wire nut for the connection.
 
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