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pen voltage tester beeps like crazy when touching kitchen hood and lamp cover

pen voltage tester beeps like crazy when touching kitchen hood and lamp cover

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  #1  
Old 09-26-19, 07:24 AM
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pen voltage tester beeps like crazy when touching kitchen hood and lamp cover

My wife got a little electric shock when she turned off the range hood this morning, so I figured I could use the non contact voltage tester to see if it would be triggered.

So when the hood was on, the tester beeps like crazy, I also used the pen to touch a few other items in my house, and at least one living room lamp also makes the tester constant beeping, is this normal?
 
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  #2  
Old 09-26-19, 07:42 AM
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I'm not a huge fan or trusting of those pen detectors.
I was given a Klein brand one and it beeps at everything (including my 2yrs old daughter who thinks its funny).
Most items should be grounded, which depending on wiring of the house (age, etc) could show some signs of current. Might be worth flipping off the breaker for the range hood and double checking all the connections inside are in good order. These hoods do vibrate and I have seen some poorly installed merets fall off over time. Doubt that is the issue here, but it would confirm its still safe and put your wife at easy that you checked it.
 
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Old 09-26-19, 07:55 AM
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Sorry a dumb question, I do have a digital multimeter, can I use it to measure the voltage on the hood? What parts the two test leads should tap on?
 
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Old 09-26-19, 08:24 AM
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sounds like the hood is not grounded. Measure between hood metal and stove metal.
 
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Old 09-26-19, 08:38 AM
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As Telecom guy mentioned, measure from the hood to the stove should give you ZERO voltage, or very very close to it.
 
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Old 09-26-19, 08:44 AM
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Thanks guys, I just tested, measuring from the hood to the stove shows OL first, then 30.x , not 0, it that right?
 
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Old 09-26-19, 09:03 AM
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measuring AC volts?

30 V is not good, if that is real.

and, do hood ON and OFF.
 
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Old 09-26-19, 09:11 AM
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Yes, AC auto mode

Hood off, 1.0xx

Hood on. 3x.x
 
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Old 09-26-19, 09:30 AM
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need to find out why hood is not grounded. Is this a ceiling mount or ??

The install manual should show grounding point withing the hood.
 
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Old 09-26-19, 09:35 AM
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That is a wall mount range hood, and there is an outlet behind the hood Chimney.
 
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Old 09-26-19, 09:38 AM
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And just to rule out the possible errors.

Will it be more accurate if I stick one lead to the ground hole on a 3 prong outlet and the other lead to the hood and test again?
 
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Old 09-26-19, 09:40 AM
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Should measure the same but you can try it.
Same for a metal sink or faucet.
 
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Old 09-26-19, 09:48 AM
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hmm, I did more testing between the hood and various kitchen items, including ground hole on an outlet, kitchen countertop, kitchen cabinet, all pretty much gave me a number around 30.x when the hood was on.

I am totally confused now.
 
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Old 09-26-19, 10:08 AM
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That is indicating a leak of 30v between the hood and ground.
There should be 0v measured.

This is a wall hung microwave/hood ?
You mentioned plug behind the hood. You need to check for ground there.
 
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Old 09-26-19, 10:14 AM
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limit voltage testing to metal objects. unless your counters are metal??

It still appears that the hood is not grounded.
 
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Old 09-26-19, 10:34 AM
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This is a wall range hood with long chimney, I will remove the chimney and test the outlet later, will provide update here, thanks!
 
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Old 09-26-19, 11:21 AM
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Ok,I just removed the chimney, inserted the test leads into the hot and neutral, reading 120.x, then move the black lead to ground, reading 120.x.

Everything looks fine, so I put the chimney back, turned on the hood and tested the hood again, this time showing me 0.00v... no idea what has happened....
 
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Old 09-26-19, 11:46 AM
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Possibly a loose ground connection in the receptacle. With a three prong plug..... it's hard to tell if all three blades are a tight fit. Usually when in doubt.... I'll replace the receptacle.
 
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Old 09-26-19, 12:24 PM
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I will get that receptacle replaced.

Question though, what might be the reason for the leak, does that mean the range hood was having problem?

Even if the ground is not working, the should not be a 30v leak there correct?
 
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Old 09-26-19, 01:00 PM
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A greasy, dirty fan motor would tend to leak a bit. Was the green wire tight?
 
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Old 09-26-19, 01:07 PM
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All the wire are in a small enclosure so I could not really check the connections. Will see if this happens again.

Thanks all for the kind replies, very much appreciated!
 
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