Hey guys I got 45 volts and 18 volts on my two legs, and 119 on the other. I figure there is a drywall screw through them, but anyone have any tips on finding the location??? thanks. Nick EC in Seattle
By the way, the ghost voltages are caused by capacitance coupling, in case you were wondering. I understand the idea but I'm not too good at explaining it. Hopefully someone else can jump in and explain it.
Re: Brown voltages on a 12-3#56917 10/08/0508:23 PM10/08/0508:23 PM
I'm going to try at any rate. First of all, a capacitor is simply 2 plates separated by an insulator.
Well, consider a piece of 2 conductor cable. What do we have? 2 charged bodies separated by an insulator - a capacitor! It should be noted that wire has extrememly small amounts of capacitance (and inductance too) at 60 hertz.
Now, the story changes entirely when we talk about high frequencies. A short piece of wire can turn into an open circuit at high frequncies due to capacitance, but that's a whole 'nother story. Let's just say I wouldn't want to be in integrated circuit design right now.
So, in the case of this 12/3 with one of the two hots deenergized, the live conductor actually induces a voltage on the other dead conductor due to capacitance. This is where I get lost in the physics of it all, so hopefully someone else can jump in.
Re: Brown voltages on a 12-3#56919 10/09/0511:52 AM10/09/0511:52 AM
More electro-magnetic induction than capacitance. IMO Think of it as a elongated transformer. It is a voltage, not usable, but not a ghost... The voltage is real on the open conductor, but if you load it with say, a Wiggy, seeing that there is no "Umph" to it, it drops out. If you grounded one side, it would be a lower voltage like ~.05-.5 on the other side. Both sides, and you shouldn't get anything...
Disclaimer: One should be very carefull of grounding unknown circuits of unknown voltages or partial nominal voltage! It may also be a resistive connection on real, and usable voltage, and result in a short.
Mark Heller "Well - I oughta....." -Jackie Gleason
Re: Brown voltages on a 12-3#56920 10/09/0512:41 PM10/09/0512:41 PM