[jabrockson]

I just replaced an outdoor light fixture - the porch light on our house. The wiring inside was relatively new and clean (compared to a lot of older wiring in our house that I have dealt with), so I'm pretty sure my wiring job in there was done neatly.

Here's the weird part (or maybe it's not weird, you tell me). I turned the light on, and when I put my hand near it I could feel vibrations in the air, like it was "charged" - like the feeling you get when the hair on your arm stands up from static electricity. The entire casing of this light fixture is metal.

So I got out my multimeter just out of curiosity. When I touch both leads to the metal casing of the fixture (one on each side) I am seeing around 2 volts AC on the meter (when the light is on).

Is any of this out of the ordinary? Should I be concerned?

 

[Yoyizit]

It should have read zero volts across a metal fixture. From the fixture to a good ground should probably read less than a volt.

Do others sense this also?

 

[goose134]

The meter should be reading potential. You should not have any potential on one side of the fixture to the other. As has been suggested, try the fixture to ground. I knew one guy who got whacked pretty good changing light bulbs in his outdoor sconces because the fixture was hot.

 

[nap]

what kind of lamp is this? fluorescent maybe? If so, the feeling you feel is not abnormal.

 

[jabrockson]

Yes, it takes one of those plug-in type fluorescent bulbs.

I'll get a reading going to ground after work tonight. Thanks for the tips.

 

[Yoyizit]

the feeling you feel is not abnormal.

Can you 'splain?

 

[nap]

Can you 'splain?

I don't know the physics of the situation but you can actually get a shock from a fluorescent lamp. I would think it is akin to static electricity which, if you remember rubbing a balloon on your hair or other fun kid stuff, you do "feel" the charge.

 

[Yoyizit]

I don't know the physics of the situation but you can actually get a shock from a fluorescent lamp. I would think it is akin to static electricity which, if you remember rubbing a balloon on your hair or other fun kid stuff, you do "feel" the charge.

This seems sort of related, unless it's faked.
http://www.youtube.com/watch?v=QzbUiLeEGZo

 

[AllanJ]

There could be phantom (induced) voltages in the metal frame of the fixture or, heaven forbid, due to a defect the metal frame could be hot. It would be better if it were grounded (a defect would reveal itself instantly by a breaker trip).

 

[micromind]

That Youtube video is as real as it gets. You can indeed cause a fluorescent tube to flash by static electricity.

If you're working near a microwave tower, you can grab one end of a fluorescent tube and stick the other end near the dish, and it'll light continuously. You won't feel a shock because at high frequencies electrons tend to travel on the surface of a conductor. In this case, your skin is the conductor, and the electricity travel only on the very outside of it.

Nikola Tesla understood this concept very well, hence he was able to become 'the electric man' without any harm. Sparks off the fingertips, etc.

If the frequency is high enough, the human body can conduct substantial amounts of current without harm.

Rob

 

[hayewe farm]

Florescent lights can build a pretty significant static surface charge. Making sure the fixture is well grounded may help some.