No Bath Lite

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  #1  
Old 08-04-15, 04:53 PM
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No Bath Lite

Have a combination bath fan and lite fixture. They are controlled by 2 switches (horizontal toggles) in a single gang box. The lite switch physically broke. I thought replacing would be rote. Black (122 volts), Red (67 volts), single white neutral and gnd. The lady says lite worked before but it will not now. The 67 volts is a mystery, but I guess that could be a phantom induced in the wire. I am now 70. Should I retire as a handyman?
 
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  #2  
Old 08-04-15, 04:58 PM
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Well this 67 year old wants to know all the wires in the switch box?

Is it a duplex switch like below?

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  #3  
Old 08-04-15, 05:55 PM
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That is exactly the switch. The top half failed physically, the toggle is gone. Lady swears it worked before breaking.
 
  #4  
Old 08-04-15, 06:34 PM
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Tell us all the wires in the switch box and how they are connected. Was the tab intact on the old switch.
 
  #5  
Old 08-04-15, 09:14 PM
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The tab was intact on only the neutral side, with the white connected. The hot side labelled A1 B1 on the old switch had the black and red connected.
 
  #6  
Old 08-04-15, 09:51 PM
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The tab was intact on only the neutral side, with the white connected.
There is no neutral side. The white wire is not a neutral. It is a "hot" wire that was not recolored some color other than white as required by code. You have a switch loop.
I thought replacing would be rote. Black (122 volts), Red (67 volts), single white neutral and gnd.
Any voltage measurement should be to ground since there is not a neutral. If standard wiring conventions were followed white to ground should be 120v. Black to ground ~0v. Red to ground ~0v.

If you get the above readings the white goes to the tab side. Red and black to the screws on the other side.

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  #7  
Old 08-05-15, 08:59 AM
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What Ray said!
 
  #8  
Old 08-05-15, 12:01 PM
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More Data

I removed the new switch and re-measured voltages:


White to Gnd 86

Red to Gnd 2

Black to GND 18

White to Black 122 (Shorting these runs the fan)

White to Red 60

Red to Black 11

I also looked in the panel. There is a black from the breaker and no grounds.
Therefore, I assume that the wires I am seeing at the switch are coming from the fan/lite or some other device inside the house. This house is 1913 construction, but the wire has plastic insulation, so it is not original. The no grounds in the panel make me guess 1960 for this wiring.

Should I pull the Lite/Fan next and see if I can sort out how this is patched together? Kind of a PITA with a ten foot ceiling and my being 5-6.
 
  #9  
Old 08-05-15, 12:25 PM
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Follow Rays wiring diagram and test.
 
  #10  
Old 08-05-15, 01:15 PM
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I did follow Ray's advice. He is correct that the white is not neutral, but hot. However, I can only get 120 across the white/black. White/Gnd is an odd voltage of 86. Since there are no grounds in the breaker panel, the bare wire at this switch must not be a true ground.
 
  #11  
Old 08-05-15, 03:11 PM
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the bare wire at this switch must not be a true ground.
Bingo! Wire my way and see if it works. If you want more proof use a reference ground or neutral. Plug an extension cord with ground into a known correctly wired receptacle and use its ground. If no grounded receptacles measure to neutral, the wide slot.
 
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Old 08-05-15, 03:51 PM
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Thanks Ray

I did wire it your way this morning and only the fan works. However, wired your way I am switching 120 v into the red, but the circuit is not closing thru the lite. I am beginning to doubt the homeowner that this was working properly prior to the switch breaking. Nothing can be trusted in these old houses. I live two blocks away and I have a circuit fed by two different breakers. Just an example of the atrocities that have occurred over a century.

Tomorrow, I'll recheck voltages with a known neutral. Thanks for that tip.
 
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Old 08-05-15, 04:01 PM
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When you are doing your checking you might be reading through a light bulb(s). This could show the voltage drop. If you bypass the switch, the light should work. If not, something else is wrong.
 
  #14  
Old 08-06-15, 01:56 PM
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Sort of Works

I took Ray's advice and re-checked voltages across a known common. Things changed. The black is hot and the white is a true common. I measured zero resistance from the white to the known common. I have no idea what the bare wire is, since there are no grounds at the panel. I still see the odd 60 volts from red to common. Wired per Ray's diagram only with the black on the tabbed side and red, white switched out.

With this arrangement, the fan works and the lite can be switched on/off only if the fan is on.
 
  #15  
Old 08-06-15, 02:01 PM
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You have the feed on the wrong screw of the switch if one switch needs to be on for the other to work.
 
  #16  
Old 08-06-15, 04:10 PM
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Find the hot wire and place it on the common screw,regardless of it's color then connect the remaining 2 conductors the the remaining screws, just curious, will the light and fan work together when all the wires are jumped together with a wire nut?
Geo
 
  #17  
Old 08-06-15, 04:22 PM
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Run the tests in post #6 using a reference ground or neutral as explained in post #11 to determine which wire to the tab side.
 
  #18  
Old 08-06-15, 10:58 PM
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I was in the exact same situation as you before and I came to this forum to figure it out and the users on here pointed me in the right direction and I was able to do it. I was replacing the same duplex toggle switch as you and there were three wires in the box (no ground). The same colors too. I didn't have a tester so I kept thinking the black sheathed wire was hot and the white sheathed wire was neutral. I kept trying so many different combinations until I posted a picture of my setup and was told white was hot and that the black and red was for each fixture. That thread should still be on here and I will put a link to it if I can find it.

Update: I looked for my old thread but it has either been deleted due to age or archived.
 
  #19  
Old 08-07-15, 08:44 AM
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I am certain the black is hot. I measured 120 from it to a known good neutral. I also know the white is a good neutral, measuring zero resistance from it thru my known good neutral. The white must be connected to the fan and the red to the lite. It would be very difficult to remove the fixture from the ceiling to see the wiring connection. Would probably have to go into the attic. I can't get back there today, but will update with any progress. Thanks.
 
  #20  
Old 08-07-15, 11:52 AM
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The junction box should be accessible by pulling the trim grid down. No need to go into the attic.

If the white is a neutral one of the items will not work. You do not need two neutrals on a device. You should have a hot and a neutral.
 
  #21  
Old 08-07-15, 12:45 PM
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I also know the white is a good neutral, measuring zero resistance from it thru my known good neutral.
A better test would be to measure voltage to your reference hot (narrow slot). It should be ~120v if it really is neutral. ~0v or ~240v means it is a hot.
 
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