Bath fan install – ground is hot w 12v
Just installed a bathroom fan in my 1950’s vintage house. My wiring is old and not grounded. My fan is a nutone from home depot. The fan is a combo with a fan and light, each run on a seperate switch. When I was finished with the install, fan and light work, I checked the metal case and ground wire, just to make sure that they weren’t hot. To my suprise, it was but only ~12 volts. When I turn the fan on the voltage will rise and fall but settle back arond 11-12 volts.
Any thoughts?
Is my only problem that I don’t have a proper ground wire run the fan fixture?
Thanks
Replies
You're picking up phantom voltage from somewhere. No big deal.
?-Phantom voltage, can you explain
I tried to once, but someone else from here kept vandalizing the explanation.
As I stood before the gates I realized that I never want to be as certain about anything as were the people who built this place. --Rabbi Sheila Peltz, on her visit to Auschwitz
Awww c'mon man, giv 'er another go....If not, this may help:http://en.wikipedia.org/wiki/Phantom_voltageScott.
you're too funny.....the author is reading this.
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'Twas not I who was the vandal. IIRC, Dan was doing a pretty good job....Scott.
yes he was, recall when this phenomenon generated all number of threads and he decided to write that.
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giv 'er another go
Do a field mapping of the vicinity of all wires and grounds. Apply Maxwell's equations taking into account inductive and electrostatic coupling.
Answer = 12 V <G>
That's the one that was vandalized. By Woodturner. Repeatedly. I got tired of correcting it and gave up maintaining it.
As I stood before the gates I realized that I never want to be as certain about anything as were the people who built this place. --Rabbi Sheila Peltz, on her visit to Auschwitz
You're measuring 12V on the fan case how? Are you measuring from fan case to a known ground, from hot to case, where to where?
If you measured from hot lead to the metal case, you are seeing phantom voltage. Digital volt meters (except for the really expensive pro models) will show some voltage between hot and anything not connected to the grounding bus back at the panel.
The old-fashioned analog meters don't show phantom voltage because the mechanism that moves the needle causes a little resistance. If you could put some resistance (like a night light or something) in series between your tester probe and whatever you are testing, the phantom voltage would go away.