UPB shocking me

DeLicious

Active Member
Hi guys,

I have a couple of SAI US2-40's installed in the kitchen which are giving me pretty regular shocks, seemingly when I touch the screw on the faceplate (which is connected to the heatsink, which is connected to the ground wire, which is connected to the... hip bone... you get the idea).

I'm guessing it's not a terribly good thing to get pretty regular shocks from these two switches :)

I opened up one of them, and all the wiring seems to be done okay. Particularly, the ground wire (which I expect would be the one to dissipate said shocks) looks okay. I don't think it's the house wiring itself as the two switches are on different breakers, so maybe one is not properly grounded, but it seems unlikely that both would not be properly grounded.

What else could be causing these shocks? Is anyone else experiencing this as well?
 
Do you have a voltmeter? If so set it on AC volts, put one lead on the screw shocking you, then take the other lead and probe it around (outside) the other switch screws, maybe even a water pipe (might have to use an extension wire).

Also, get one of those three light testers and see if you do have a correct wiring scheme in nearby outlets. It will not tell you the status of the box where the switches are, but at least it will give you an idea if correct polarity and grounding methololigies were used in the house/breaker box.

I'm wondering if something isn't wired correctly or maybe a wire knicked in the box, touching a ground wire.

I've already seen romex running over a water pipe and with the slight vibration of the water pipe over the years, it wore a small hole in the wire causing live contact with that pipe.
 
Just an observation from one of these switches as I was looking into it. When the load is inactive, only the power line shows current (through my no-contact detector). When the load is active, all the wires (power, load, neutral, and ground) are shown as active. Is it normal?
 
BraveSirRobbin said:
Do you have a voltmeter? If so set it on AC volts, put one lead on the screw shocking you, then take the other lead and probe it around (outside) the other switch screws, maybe even a water pipe (might have to use an extension wire).

Also, get one of those three light testers and see if you do have a correct wiring scheme in nearby outlets. It will not tell you the status of the box where the switches are, but at least it will give you an idea if correct polarity and grounding methololigies were used in the house/breaker box.

I'm wondering if something isn't wired correctly or maybe a wire knicked in the box, touching a ground wire.

I've already seen romex running over a water pipe and with the slight vibration of the water pipe over the years, it wore a small hole in the wire causing live contact with that pipe.
No, I don't have a voltmeter... are they expensive? I could easily go to Home Depot to get one. How long are the leads? There aren't really any water pipes near where the two switches are.

Also, can you explain more what a three light tester really is? All I have is a no-contact current tester to tell me if a wire is hot or not.
 
well, i went out and bought a multimeter... it seems to detect volts on an outlet okay. however, putting one lead on the screw and the other lead on various metal objects close by shows nothing... will any metal object do, or does it have to be a water pipe or sink or something?
 
Just as a FYI,

I had a similar weird problem years back where I would get a mild shock when touching a shower head in my house, occasionally, (ya, that made for interesting showers.)

My problem turned out to be a loose ground lug in the electrical service panel. It may be worth having someone check that. In some houses, like mine, the electrical service ground is also connected to the copper water pipes. So, I was actually providing the ground by touching the pipe while standing in a wet shower. :lol:

Also, I would try the voltmeter to a point connected to the drain (assuming metal pipes). If you can feel it, it is there (as far as electricity goes).

Ken
 
DeLicious said:
Also, can you explain more what a three light tester really is?
A three light tester plugs into a three prong outlet. It will tell you if you are missing the ground, have neutral and hot reversed, have an open neutral, an open hot, hot and ground reversed. Some even include a push button to test a GFI circuit.
 
KenM said:
Just as a FYI,

I had a similar weird problem years back where I would get a mild shock when touching a shower head in my house, occasionally, (ya, that made for interesting showers.)
That's too funny! :lol:

I had the same thing about 5 years ago but I don't remember what was causing it. My wife's cousin is an Electrician so he fixed it.
 
I agree it could be any of those electrical gremlins, but are we sure its not good old fashioned static discharge?
 
just as a question that i didn't get an answer to earlier, is it normal for a ground wire to be hot when the load is activated?
 
DeLicious said:
just as a question that i didn't get an answer to earlier, is it normal for a ground wire to be hot when the load is activated?
If you measure between the hot and neutral, you should have 110 volts. If you measure between the hot and ground, you should have 110 volts. If you measure between the neutral and ground, you should have 0 volts.
 
Your lighty-up-tester may indicate voltage on your nuetral when there is a load on the circuit. It may just be reading the induced voltage from the line & the switched conductor. Those are not exactly accurate. It sounds like there may be a loose connection or joint in the nuetral wire at some point in the circuit. I would recomend having a qualified electrician check it for you. It may save you from damaging your switches or yourself. Just today heard about electric shocks and "exited delerium". 'Don't think you want any of that! Good luck

CDC
 
DeLicious,

Again FYI, and as one who has been shocked by most everything (electrical) at one point in time. :lol:

If it is a static electricity discharge, you will get one little zap, sometimes you can see the spark and hear a small snap as the electricity discharges.

If you feel a continuously type of 'zap' then the problem is most likely a messed up AC circuit ground somewhere.


;)

Ken

Edit added:

To avoid giving the wrong impression, I will add;

I have been working with DC and 120 AC electronics since I was about twelve, I am fifty-three now. I can even tell you how badly 400 hertz (joke). I am not careless, this is just a lifetime of working with things that can make sparks.
k
 
I will add that it is a VERY dry "staticy" time in winter.

In my house, I have a couch that when we do not run the humidifier, will charge "your butt", when you get up, and touch anything you get a zap. Especially that metal thing that put on corners of walls where the dry-wall meets. That metal thing must have 100's of zaps from me. It's the ONLY part of the house that gets like that.

So, if it IS static, then your wiring IS correct. You are discharging excess "crap" voltage through a proper channel.

Again, IF it's static. From the sounds of your probing, that may be what it is. If in fact it is static, you may need to get a humidifier. That will dramatically cut down on the static.

--Dan
 
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