Step-by-step for unravelling 3 and 4-way switches?

Ok, I am very slowly beginning to understand this.

I understand now that the common off a 3-way switch isn't a matter of choice...it's a mechanical fact. So it's definitely the one marked "common", and with the off-color screw.

So, the point of the 3-way switch is to connect one of the two other wires to the common. If I take one of those two wires...and wirenut it to the common wire...then it's like I've "frozen" that switch in one position, right? Because then...the other switch WILL turn the light on and off by itself.

So if I REALLY wanted to get fancy, and to make sure that switch A turns the light on when it's up, and off when it's down...then while the power is on, I should manipulate the switches so that switch A turns the light on when up, and off when down. Then, turn off the power, remove switch B, and wirenut together the two wires that had been connected as a result of the switch position. (which, once I remove the switch, I can use my continuity tester to see which wire was connected to the common).

Then, going back to switch A, I'll now know which wire gets connected to the common when the switch is up, which means the OTHER wire is no longer being used. I can then turn the switch off, and with the power on, the wire that has no voltage is the switched hot, and the other is the hot hot.

Have I finally figured it out???

<_<
 
beelzerob said:
Then, going back to switch A, I'll now know which wire gets connected to the common when the switch is up, which means the OTHER wire is no longer being used. I can then turn the switch off, and with the power on, the wire that has no voltage is the switched hot, and the other is the hot hot.

Have I finally figured it out???
Click to expand...

I think you have.

There is still a chance that you are switching neutral and not hot, however. But I am sure you'll figure that out. You also might be able to simplify things some too. If the 14/3 in box B really goes back to box A you really dont need to power that loop at all. You could ignore all three wires. From the pictures, you seems to be powering either the white or red, but in box B you'll have connected either the white or red to the black which just goes back to box A.

I have to admit though that your pictures confuse me a bit. The two red wires going to the switch imply they are coming from two different 14/3. So either power is being fed to the switch via a red in one 14/3 or the load is being controlled by the red of a 14/3. Either case is a bit odd. My sense of curiosity would have me digging deeper. But, you do seem to have enough information to get the get the job done.
 
Well, it's possible the traveler from switch b goes to switch A.

I see what you're saying...if that wire terminates in switch box A, then there'd be no need for the electricity to make that round trip...just completely disconnect it in switch box a.

I guess to learn that, I'd have to disconnect everything and then, what...tie some to ground and check them for continuity? Or it's not that long a stretch, I could use extra wire to check both ends of the wire for continuity.


So to summarize my revelation from last night.....

If you went to a switch and turned it on and the light came on...then turned it off and the light went off...as far as I was concerned, that'd be a 2-way. So if I NEVER switched the other switch, then it'd act just like a 2-way switch. So if I remove the other switch and wire nut together the connections it had, then I would be permanently fixing that switch in that position. Right?

correct me if I'm wrong...but wouldn't that same thing apply to 4-way switches? I know they work differently, as they flip the wire connections. but again, if I just removed the switch and wirenutted the wires that had current going through them, then the one remaining switch would work like a 2-way, right?


So what you're saying is that the remaining connection on the single remaining switch might be switching the neutral (post-load), and not a hot (in other words, pre-load) wire? I didn't think they put neutrals through switches, I thought those were always wirenutted together.
 
When you hear hoof beats, think horses, not zebras first.

I wouldn't worry that your switches are wired to switch neutral, as I'm not aware of that being a recommended/common practice. (I just play sparky in my own house and on the 'net and patiently walk my dad through electrical questions over email...but I'm no pro.)

Based on your reflected words, you're understanding what I was suggesting. Is it not working the way you expect? (I'm reading the thread in fragments over time, so apologies if you said so 8 posts ago and I missed it in my one-post-at-a-time while procrastinating mode.)
 
Oh, I haven't actually made the change yet...by the time the light bulb came on (over my head), it was after 11p, and I decided it was too late to commit to it.

But now that I've had a night to sleep on it, and some extra confirmation that it really IS as easy as it now seems....I'm goin' for it!

The only thing I'm left pondering is....if that traveler wire goes from switch B straight to switch A, and so I could completely disconnect it...then I could actually use those 3 wires to carry my aux switch signals over to the master switch. That would help, as I don't currently have any cat5 run to where the aux switch will be....

HOWEVER...among the many ways that's a BAD idea are....it'll put LV and HV in the same box. And even though OnQ provides a 600V rated sleeve to put over the wiring in case you do that, I'm still trying to avoid it. Plus if I ever want to go back to normal switches, or the eventual new owner of our house does, I'd hate for them to get that mixed up at some point.

So...I guess I get to run new cat5 wires! Actually, I can just re-purpose some cat5 I already ran to the top of the garage that I haven't found a use for yet anyway.
 
Would it be any problem for an ALC switch if the switch is not on the 'hot' side and thus controlling the hot wire to the light but rather on the 'neutral' side and thus controlling of the light is connected to the neutral?

I sort of thought this was goign to be simply, but am getting a bit worried now....

Will see how things work out when i get home and start tearing the faceplates off and switches out.

I thought the ALC switch connects to both Hot and Common and then has a 'switched' output. Does this output represent the connection to the hot or the neutral...indeed the more i think about it the more important this seems. In the end i don't think it can be showstopper because i thought any switch can be replace by a dimmer which is essentially what an ALC switch is.
 
Well, I know there IS a neutral in the box...they're all tied together. I'm assuming I can just tie my ALC switch into that bundle of neutral and not worry about what light it is connected to.

It might be a question for Tony on whether or not it's ok to have the ALC switch before or after the load.
 
Beelzerob: are you posting the question in the really long cat5 lighting/ALC thread?

I guess the proper terminology would be having the ALC switch at either 'hot' or the 'neutral' side of the load since it's AC and there's really no before and after.... :)
 
Well, success!

The bottom line is that it now works. I've removed one switch, and replaced the other with an OnQ switch, and it works! While I was at it, I removed the other switch that was in that box and tied its wires together too, as that switch is next on my list.

Easy, once you understand it.
 
Hehe...ya, only 3 pages....

Ya, this was my 3rd attempt at understanding 3-way wiring. I had pulled all the switches out and looked at it...and then put it all back and decided it was time to get an electrician involved. then when the Finance Ministress put a hold on that for several weeks, I decided it was time to tackle it again.

I think what finally clicked for me was I was reading other forum postings that google gave me for how to undo a 3-way. And those still weren't making any sense. But this one scenario involved a guy removing a light switch they never used. And I thought "well, you can just "lock" the switch in its current position, and then as far as your other light switch is concerned, it IS a normal switch." *ding*

So that's what finally did it for me. Wire the other switch wiring into a permanent configuration, and your remaining switch becomes a normal switch.

All that talk of travelers and neutrals and commons (oh my!) just wasn't helping.
 
Not too long ago in a new home I was having a problem with some outside floods. There were five different sets of floods (five circuits if you will) and two of the sets where supposed to be controllable from two different locations. We had been living in the house for sometime before we really had an occasion to use these floods.

Who ever wired them was seriously confused. I found that throwing certain switches would turn ON one set of floods and turn OFF another set.

So I called in a long time friend and master electrician and he was simply amazed at the mess. It took him a while but he eventually traced all the wiring and was able to determine how the switches should have been connected, which he did for me.

So whoever the builder hired to do the wiring (it as a regionally known large builder) found 3-way and 4-way confusing.
 
I had a similar problem with my builder. His electrician wired a 'basic' 3-way switch incorrectly. It took me a few weeks to figure this out, as I refused to believe that a licensed electrician would screw something like that up.
 
I am scared now...after i had gone though with the sparky in the house during the pre-install walkthrough he said he's never seen so many multi-ways in a house of this size...

Hopefully they knew what they were doing... or i'm in deep $^%&*
 
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