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3 way Wiring question

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henrylr

New Member
Hi all,

I have a basic question about 3 way light switches, and don't know if this is right place to ask, but you guys have helped me in the past so here it is.

I just had a 3 way switch fail. There are 2 switches that control a light on the second floor. The first floor switch is a modern 3 way. The failed switch, on the 2nd floor, is an old hubbel rotary made before 1904. Both switch boxes have 3 wires as follows: first floor has 2 travelers and one neutral to ground. I checked it with my meter and it is the only wire, in either the 1st or 2nd floor boxes, that shows the black wire at the light fixture is the 120V power from the source. The 2nd floor box has 2 travelers and third wire which runs from the white wire at the light, where the hot black wire is located. There are no other wires at the light fixture. I have been searching the web but have not found an example of my wiring. I am hoping someone can help with this wiring problem.

Thanks,
henrylr
 
hi,
This image is the usual connection way for stair way lighting switch wiring.

Sorry, site software will not allow me to upload my GIF or PNG drawings.:(
E
 
I am assuming you are wired like this. Very bad. The hot and the neutral are switched. You should never switch the neutral.
 

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  • 2 WAY LIGHT.jpg
    2 WAY LIGHT.jpg
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Your drawing has captured the layout. It has been, working, like that for about 110 years. As your sketch shows, the hot line from source goes to the light's center connection and, the white wire is connected to the light's side/neutral connection which somehow ends up being the wire connected to com on the first 3 way switch. Why is this bad and does it violate the electric code in Ct?
 
:nailbiting::nailbiting::nailbiting:
Your drawing has captured the layout. It has been, working, like that for about 110 years. As your sketch shows, the hot line from source goes to the light's center connection and, the white wire is connected to the light's side/neutral connection which somehow ends up being the wire connected to com on the first 3 way switch. Why is this bad and does it violate the electric code in Ct?

Hi

It's bad Because if you switch neutral, the circuit is still "hot". If you touch any part of the circuit (as when working on the socket or switch) and also come into contact with neutral, or ground, you can get zapped...or worse...killed by electrocution..:nailbiting:

eT
 
Last edited:
Hi all,

I have a basic question about 3 way light switches, and don't know if this is right place to ask, but you guys have helped me in the past so here it is.

I just had a 3 way switch fail. There are 2 switches that control a light on the second floor. The first floor switch is a modern 3 way. The failed switch, on the 2nd floor, is an old hubbel rotary made before 1904. Both switch boxes have 3 wires as follows: first floor has 2 travelers and one neutral to ground. I checked it with my meter and it is the only wire, in either the 1st or 2nd floor boxes, that shows the black wire at the light fixture is the 120V power from the source. The 2nd floor box has 2 travelers and third wire which runs from the white wire at the light, where the hot black wire is located. There are no other wires at the light fixture. I have been searching the web but have not found an example of my wiring. I am hoping someone can help with this wiring problem.

Thanks,
henrylr


Please consider using an electrician to repair your problem.

Here is the basic 3 way switch connection diagram.

untitled.png
untitled.png
 
Parts of my house has old post and knob wiring at some light fixtures. I have run bx and romex to other wall outlets but 4 ceiling light fixtures are still on post and knob. Is that bad or violating code?
 
Sorry, site software will not allow me to upload my GIF or PNG drawings.:(E
The new software on this site takes A LONG, LONG TIME to upload a PNG image.
I almost gave up, had dinner then found that it did finally upload my image. It is much slower than dialup.
 
Interesting/confusing national differences in terminology. The setup shown in post #6 would be called a 2-way system here in the UK. A 3-way system here has 3 switches; two end switches being SPDT and the intermediate one being a DPDT type.
 
That is an old one. Originally the neutral was switched and the device was "hot". This allowed the electrician to test the circuit by just apply a ground. As others have stated this was changed for safety reasons. Anyone know when?
 
The wood in that old house must be so dry that it will probably catch on fire if you look at it. Keep electricity away from it!
 
Interesting/confusing national differences in terminology. The setup shown in post #6 would be called a 2-way system here in the UK. A 3-way system here has 3 switches; two end switches being SPDT and the intermediate one being a DPDT type.

Interesting/confusing national differences in terminology. The setup shown in post #6 would be called a 2-way system here in the UK. A 3-way system here has 3 switches; two end switches being SPDT and the intermediate one being a DPDT type.


Here , and in the U S , that would be a four way . That is 2 3 way switches and 1 4 way switch.

With this system you can switch from many locations !
 
The new software on this site takes A LONG, LONG TIME to upload a PNG image.
I almost gave up, had dinner then found that it did finally upload my image. It is much slower than dialup.

hi agu,
Normally [ whatever that means] my uploads are fast, sometimes there is a short delay before it starts uploading.
On that post, the software refused to accept my uploads.?
E
 
hi,
This image is the usual connection way for stair way lighting switch wiring.
hi,
Retrying the image upload from Post #2
E
 

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  • AAesp01.png
    AAesp01.png
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