A while back I was asked to look at a kitchen ceiling fan/light that was supposed to wired with a 3way switch. The 3way did not work properly, only one switch worked the light, and then only if the other switch was flipped one way.
Did not spend much time fooling with it, the whole house had a lot of electrical issues… Something made the think that maybe there were 2 separate feeds going to the light. I recall reading/hearing somewhere that there was an “old fashioned” unsafe way to make a psuedo 3 way switch running different circuits to the same fixture.
Anyone heard of this? Not that I would do it that way, just curious if my hunch was right.
Replies
> The 3way did not work properly, only one switch worked the light, and
> then only if the other switch was flipped one way.
The two switches simply are not wired correctly. Assuming both of the switches actually are 3-way, it sounds like the line to the light is connected to one of the poles that is supposed to be connected to the master 3-way.
> I recall reading/hearing somewhere that there was an "old
> fashioned" unsafe way to make a psuedo 3 way switch running
> different circuits to the same fixture.
No. You can hook up two single pole switches to the same light and turn the switch on from either location, but you will have to turn both switches off to get the light to go off. It also doesn't matter whether you have the switches connected to different circuits or to separate ones. Where it gets dangerous is when you have the two switches connected to different circuits and the two circuits are on different legs of the service.
Yep, with knob and tube there was as different way of doing it. The light was wired between the two common terminals on the two switches, and hot and neutral wired to the other two terminals on each switch.
It was not uncommon for the two switches to end up on different circuits, and if the house was subsequently converted to 240V (most K&T was originally 120V) it was possible for the two sides to end up on opposite sides of the 240V line, meaning that your four possible combinations were on, off, on, and poof!
In your case it could be that one circuit has been abandoned and is no longer connected to hot.