Three way switch with extra wires

Status
Not open for further replies.
G

Greg1707

Senior Member
Location
Alexandria, VA
Occupation
Business owner Electrical contractor
I swapped out two-three way switches at a house built in the 1930s. The first switch was normal with only three wires in the box and no neutral.

The second switch had one wire on the common screw and two wires on each of the two traveler screws. Once again no neutral present.

This would suggest the traveler wires were middle of the run?

Any idea of what this could be?
 
The feed is at the light so the neutral doesn't need to come down to the switch... Of course those were the old rules why they drew the yellow as ground is beyond me.



5fcbae213038f408d1162ffc711220c3.gif
 
Was it K&T wiring?
You sure there were no neutrals?

Usually see this scenario where H+N are connected to traveler screws and jumpered to the next switch, also on traveler screws. Then from both common screws will be a single conductor to the light.

I can't think of any other scenario where you would have five conductors in the box and all five connected to the switch
 
Illustration presented by Dennis is the most likely scenario for the wiring. Have seen this a lot in old houses, most likely originally had a pull chain switched lighting fixture. And then at a later renovation decided to have wall switches installed. Drop the light fixture and you will likely find the "missing neutral". With this setup you can run into some very old and likely brittle conductors on the power feed. Most times HO have installed bulbs in excess of wattage limits of fixture causing heat damage to conductors.
 
Fred B said:
Illustration presented by Dennis is the most likely scenario for the wiring.
Click to expand...
I'm curious. I don't see five conductors on one switch in the illustration that Dennis provided
🤔🤔

OP said one switch has 2 conductors on each traveller screw (2x2=4) + 1 conductor on common screw
 
James L said:
Usually see this scenario where H+N are connected to traveler screws and jumpered to the next switch, also on traveler screws. Then from both common screws will be a single conductor to the light.
Click to expand...
This sounds likely to me. A simple solenoid-tester test against an extension cord would tell you quickly.
 
Sounds like a California 3-way, the hot & neutral is on the travelers and the light is on the common. The 2 extra wires could be a feed through to something else.
 
Little Bill said:
Sounds like a California 3-way, the hot & neutral is on the travelers and the light is on the common. The 2 extra wires could be a feed through to something else.
Click to expand...
I think it could be #2 in the diagram below, which is what I understand to be a California 3-way.

3-way_switching.PNG

The extra two wires on the traveler screws of one switch would be a hot and a switched-hot, and these form a switch loop that likely goes to the light.
 
It could also be as described earlier: Fig. 2 with the hot and neutral on B and C, respectively, and the light wired between the commons, where the letter A is.
 
LarryFine said:
It could also be as described earlier: Fig. 2 with the hot and neutral on B and C, respectively, and the light wired between the commons, where the letter A is.
Click to expand...
The OP said there was no neutral at either switch. But perhaps he saw no wires besides those going to the switch, and therefore just assumed there was no neutral present.
 
synchro said:
I think it could be #2 in the diagram below, which is what I understand to be a California 3-way.

View attachment 2557234

The extra two wires on the traveler screws of one switch would be a hot and a switched-hot, and these form a switch loop that likely goes to the light.
Click to expand...
Y'know, you might have hit a home run with your #2 diagram.
I've never seen it like that. I'm gonna have to file that in my mental rolodex
 
It was common to find switching in either or both conductors back in the days of K&T, especially before system grounding became the norm.
 
James L said:
Y'know, you might have hit a home run with your #2 diagram.
I've never seen it like that. I'm gonna have to file that in my mental rolodex
Click to expand...
I didn't draw the diagram. It was posted on this forum several years ago, and so I decided to pilfer it because it matched what I was trying to convey. ;)
 
Status
Not open for further replies.
Top