3-way Light Switch Confusion...

[Jolly Amaranto]

Originally Posted by svandamme

why would you want 2 switches to turn 1 light off?

If you want to turn on a light from two different locations like two entries into a large room, long hallway, top and bottom of a stairway etc.

As we all agree, that one solution only solves half the problem, you want to be able fully operate it from both locations.

[gacook]

You are correct in your thinking of how it's supposed to work.

Fault sounds like some sort of short in the line. I've had one where both switches had to be just right in order to work.

[svandamme]

Originally Posted by Jolly Amaranto

That was over simplified circuit diagram just showing the current carrying wires. I did not show the ground. SNIPYou can buy it in bulk and get a better price on it. To run a proper 3-way circuit you need three conductor + ground or four wire cable which costs more and you only need it for that one circuit. Therefore if you are cheap and lazy, you just use what is on hand. And if you are a cheep guy you go for the standard light switches which are less expensive too. A simplified house wiring for a three way light circuit would need standard cable to the light box from the breaker or fuse box and extra conductor cable from the light box to each switch box. This illustration shows a cheap way of doing it. Or you could run it more like the original posters diagram and run the power to one of the switch boxes and still have the same outcome in the end.

Same wire in plastic here.
100 meter roll is 130 bucks or so for 1.5mm copper . Which is fine for lighting
2.5 is more expensive

Either way. The both off for off setup wont save much wire. For much annoyance qnd little useful functionality

[Robert Coats]

Originally Posted by MBAtarga

Robert - do the switch toggles have labels of ON/OFF?
If they are 3 way - they will NOT have any labels as the label would be irrelevent.

I will take a bright light and see if either toggle in embossed with ON or OFF, and might even pull the plate an peer inside to see what back magic is contained within. (I know, I know, don't let the smoke out...I'll be sure to close the 'smoke valve' in the electrical panel first).

[dad911]

Or put in a smartswitch and say 'Hey Google turn on the Hallway Light'

[chrismorse]

I just went through a 3 way system, next door.

First you need to determine which side supplies the circuit, (always hot and consistent nutral/ground).
Then run a continuity check, to verify no shorts of opens.
Bench test your switches, not all of them have black "commons", or they may not be in the same places on both switches. This can get confusing and i think this is one of the major sources of 3 way inconsistencies.
chris,

[3rd_gear_Ted]

"Only God and electricians can make light"

[jcommin]

Originally Posted by A930Rocket

All I know is, they should work like you first described. If they don’t they are mis-wired.

+1 There is only one way to do it, anything else is mis-wired. The mis-wiring appears more common than I would have thought. My son bought a home built in 2006 and 3 swathes in the home were mis-wired.

[Amail]

I just remodeled my kitchen and wanted to control the "stadium lighting" from three locations. Turns out there's such a thing as four-way switches; didn't know that! You need four-way switches in the middle of the circuit bookended by three-way switches. I was heartily impressed with myself when I'd finished and found it worked like a charm. I did end up buying a crap-ton of 14-3 wire though.

[svandamme]

Originally Posted by Amail

I just remodeled my kitchen and wanted to control the "stadium lighting" from three locations. Turns out there's such a thing as four-way switches; didn't know that! You need four-way switches in the middle of the circuit bookended by three-way switches. I was heartily impressed with myself when I'd finished and found it worked like a charm. I did end up buying a crap-ton of 14-3 wire though.

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3-way Light Switch Confusion...