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View Full Version : Low voltage, 35, 68 volts, testing Circuit - STRANGE!


axelworks
May 28, 2007, 09:09 PM
OK,

I need all the help I can get on this one. Please see attached picture.

Let me keep it simple. I'm installing a new circuit for 2 new ceiling fans in my house.
I ran 12-2 from a new 20 Amp breaker into the ceiling where the first fan will be. From the ceiling box, I ran 12-3 down to the switch box.

I tested the 12-2 line from the breaker - 120 V - looks good. Now, when I hook up any one of the wires from the 12-3 to the hot from the 12-2, I get the following test (see pic)

Gnd -to- White/ w/ blk stripe -- 120 V
Gnd -to- Red -- 35 V
Gnd -to- Black -- 68 V

Note: The wires are not connected to any switch or device - there is nothing else on the circuit, I ran the new circuit myself. The wires test the same in the ceiling as at the switch box (as described above).

Is there a cut wire leaking the voltage to Red and Black, What is going on!!

Thanks
-Ax

Stratmando
May 29, 2007, 07:06 PM
I take it, the top and left(Orange looking wire, I assume is supposed to be green,Ground.
If not it should, and identify with green.
White, neutral from panel goes to fan white ONLY.
White in switch box should be taped black, That is your hot to 2 legs(red & black to fan)
At the fan box, connect White from switch to black from panel.
I think the odd voltages are backfeeding through motor.
Above should work.

Stratmando
May 30, 2007, 07:50 AM
You never switch neutral by itself.
If you wire like I describe, 99% chance it will work.
It is exact, and can't miss any steps.
If you don't understand, read slower, this will work.

ceilingfanrepair
May 30, 2007, 01:47 PM
Are you using a digital meter?

Have you tried it with the fan and switch installed to see if it works as it should?

Where's TK when we need him?

ballengerb1
May 30, 2007, 02:56 PM
Hayne, fix your diagram and repost. Grd to white = 120?? Go back to your panel or box and take a second look where you tied your white. It appears you tied the white to the black, not correct at all.

tkrussell
May 30, 2007, 03:12 PM
Since alex states that the wiring is in place, unconnected to anything, and is reasonable to expect no readings, a good test to confirm or deny a short in the wires in this one cable, use a good quality digital meter with ohms setting and you should measure close to .09 to.1 ohms, assuming the cable is about 25 feet long, testing each wire across each other and the ground wire. Any less resistance will indicate a short in the cable.

It also can be caused by either false readings on a not so expensive meter, and/or induced voltage on these wires due to something the cable runs near, or if the slack of the cable is coiled someplace, worse if the coil is adjacent to other live wires or equipment.

axelworks
May 30, 2007, 04:36 PM
OK,

I have to thank TK for accurately reading the diagram and explanation I included - I will give those suggestions a shot tonight and see what I can come up with.

Thanks!
-Ax

Stratmando
May 30, 2007, 06:35 PM
Axel , Tk is good, did you try what I said Or are you insisting on switching neutral.
bhayne, he is not showing motor, but 3 wires shown, white from panel to fan white,
Red to Light and black to fan would work.
That White wire with black tape needs to be hot to feed switches.
And If you are thanking TK for undrstanding Neutral is switched, I am confused.
You say you ran the wire, Did you BEAT, NICK, CUT, MANGLE WIRE. If you didn't.
Then please read and follow instructions, You can't make me think switching neutal is
Right.
I guarantee Voltage radings were from switch box with fan installed, If you did .
PLEASE TRY MY METHOD.
You drawing does not work. My first post works, what are you waiting for.
If I am wrong, It is because you PHYSICALLY DESTROYED WIRES.
I don't believe you did that. Please try.

Stratmando
May 30, 2007, 06:48 PM
Top and left, orange looking wire would be ground(Green), Pigtail and connect to fan ground.
I think some of these post are assuming you have tried previous and did not work.
I think the 2 ODD voltages are one is going through motor wndings, and 1 is going through bulbs.
I respect the opinions and advice of 4 people(at least) on this post, If I am wrong, some one tell me.
I don't want to compete.

After that, at switch box, Red and black can be switchlegs, green ground, White(reidentified) is feed to switches.

axelworks
May 30, 2007, 09:56 PM
Strongbad, I need you to relax for a second:

I did a resistance test for each wire -- each wire read about 0.2 ohms on my meter ( Fluke 177), so I figure that's not the issue.

Next step::::

I decided to try hooking up a different 12-3 wire that simply dangles from the ceiling down to the floor, and do the same tests there; again, NO switches, NO fans connected. (See illustration attached.)

The resluts were great! - I think my house was built on some ancient burial ground or something - the whole thing is ridiculous. (See the test results in the illustration.)

TK - you're my only hope.

-Ax

tkrussell
May 31, 2007, 02:47 AM
It seems to be just induced voltage. I am sure this is nothing to worry about.

Stratmando
May 31, 2007, 05:27 AM
Your new drawing is how I explained. I agree with TK, probably induced, not to worry.
Replace wire, or hook up fan. White at switch is your hot, and red & black switchlegs.

Or try this.with breaker off, connect hot(White w/black tape) to red and black.
Install fan, and connect, turn on breaker. Fan and light should come on, check
Pull chains, if not.
Did you use "Bad wire"? Change wire, or hook up fan.

axelworks
Jun 5, 2007, 07:36 AM
Well,

I hooked up the fan and switches, and everything seems to work OK, except for one strange item:

When I test the light socket w/ the switch OFF, there is about 11 to 12 V between the leads. With the switch turned on, a good 120 V shows up. Still just a harmless induced voltage?

Ax

labman
Jun 5, 2007, 08:06 AM
If as TK suggested, the voltage you are picking up is from an adjacent wire, try touching the base of a 120 volt light bulb to the 2 wires with 75 volts. The bulb shouldn't even glow dimly.

Stratmando
Jun 5, 2007, 09:14 AM
My first post, I feel you think it is wrong. Did you buy a bad wire? I would get rid of that meter, Maybe get an analog.
Try a 12 volt bulb?

ceilingfanrepair
Jun 5, 2007, 12:06 PM
Don't worry about what the tester reads, sometimes digital testers get phantom readings. If everything works as it should then you're good.