# Three and Four way switches



## jett95 (Sep 18, 2012)

Remember, one common feeds the circuit and the other common switches the circuit. All you ever need to know


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## Dennis Alwon (May 9, 2009)

sirux said:


> I'm a second year apprentice and I still suck at Three and Four way switches. Are there any tips or drawings I can do to become more skillful in that area?
> Thank-you


Do a search on the web as there are many hookups to study-- Of course the neutral would be running thru the boxes and just spliced there

Here is one


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## wildleg (Apr 12, 2009)

try thinking of it this way (minus ground, neutral):

a three/four way is 2 travelers from one end to the other
at one end the point wire is a feed, at the other end the point wire is the load

line ----<3way>=========<4way>========<4way>=====<3way>-----load

(sorry too lazy to draw it)

does that help any ?


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## backstay (Feb 3, 2011)

sirux said:


> I'm a second year apprentice and I still suck at Three and Four way switches. Are there any tips or drawings I can do to become more skillful in that area? Thank-you


It's something that will come with time. Romex is easy, if you are on 3ways you have a 14/2 and a 14/3, the 14/2 black will go to the black/copper screw. The 14/3 black/red will go to the brass screws. Whites tie together. 4ways the cables go to opposite ends, whites tie together. When lights are in the middle it's different of course, but get the easy one down in your head, then you can move on.


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## 480sparky (Sep 20, 2007)

backstay said:


> .....4ways the cables go to opposite ends,........


Not always. :no::no: Some are switched side-to-side.


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## backstay (Feb 3, 2011)

480sparky said:


> Not always. :no::no: Some are switched side-to-side.


 I know, hate that. I always meter check if they don't come in their own box.


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## waygone (Nov 10, 2011)

For some reason I can't visualize it.. I'll just draw it out a million times until I can.
I can visualize a whole control panel but not a simple circuit.. lol I suck
Thank-you for the advice guys.


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## waygone (Nov 10, 2011)

I worked on a ship for 3 years where we had no neutrals, everything was 2 wire 60V each lol


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## Awg-Dawg (Jan 23, 2007)

sirux said:


> For some reason I can't visualize it.. I'll just draw it out a million times until I can.
> I can visualize a whole control panel but not a simple circuit.. lol I suck
> Thank-you for the advice guys.



Check out youtube.


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## 480sparky (Sep 20, 2007)

sirux said:


> For some reason I can't visualize it.. I'll just draw it out a million times until I can.
> I can visualize a whole control panel but not a simple circuit.. lol I suck
> Thank-you for the advice guys.



Think of a couple of 3-way switches as a pair of SPDTs.


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## chicken steve (Mar 22, 2011)

Get yourself a battery, a lamp, some wire & some switches

and start playing with it all

~CS~


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## Big John (May 23, 2010)

sirux said:


> I worked on a ship for 3 years where we had no neutrals, everything was 2 wire 60V each lol


 Did you have 4-ways on the ship? What was the difference?


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## waygone (Nov 10, 2011)

We didn't have 3 or 4 ways on the ship


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## ablyss (Feb 8, 2014)

It takes a while for it to click. But when it does you will feel it. It's an amazing feeling learning the trade. I have a saying if I learnt something today it is a good day. 

Keep in mind if you erase all the complexity from the sketch pad in your mind and look at what is essentially required for any circuit you are left with a simple series circuit; A conductor, a resistor and some electricity.


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## Big John (May 23, 2010)

Two 3-ways with a 4-way in the middle. The pair of conductors are the "travelers". Each end is a "common".


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## LGLS (Nov 10, 2007)

A good way to learn them is to buy 2 knife switches spdt, and a 4-way toggle. Then wire them up on a board where the feed and the load can be changed to any of the 3 switch locations. Then experiment at all the different combinations. The "visualization" technique doesn't work for everybody, but if you can visualize that all a 3-way does is choose which of the 2 travelers the common is making contact with, and that the lamp will be on when both 3-ways agree on the traveler. You have to fully understand that and mentally grasp it in order to proceed.

Visualizing what a 4-way does is just as easy in that it just reverses the 2 travelers in with the 2 travelers out. That is why you can have an unlimited number of 4-ways between the 2 3-ways.


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## 480sparky (Sep 20, 2007)

A 3-way switch is attached to two wires that go to the other 3-way switch: One is energized, the other isn't. The other 3-way is connected to one of those wires. If it's connected to the energized one, the light is on. If it's connected to the de-energized one, the light is off.

Any number of 4-ways in between merely switch those two wires around.


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## chicken steve (Mar 22, 2011)

ok, now that we've gone that far, feed &switch a 4W :whistling2:~CS~


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## The_Modifier (Oct 24, 2009)

Or you can do what one of my journeyman did (waaaaay back in my apprenticeship days) . Took a perfectly good 3 way and a 4 way and opened them up for us to see the insides. His theory was that if he took the time (and spent the money on the switches) we would better understand how it works and possibly work safer.

When one of the other apprentices asked how a contactor worked, we stuck with the diagram, lol. Those where too expensive.:laughing:


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## Drakhen (Mar 2, 2014)

For three ways, the explanation that finally stuck with me is that you need 3 things for it to work.
1: Power on the common screw of one switch
2: Switch leg on the common screw of the other switch
3: Neutral heading up to the light

So if you have your power and sl in the same box, you can splice the neutral right there, and have #3....so you will just need to send the power or SL to the other other 3way down the black wire of the 3wire which will let you settle #1 & 2

If your power and switch legs are at opposite ends of the 3way then you already have #1 & 2 fulfilled and you will need to bring your neutral from the power switch box to the other side using the white wire and onto your light fulfilling #3.

Your travelers for your 3 ways will end up being the two other wires in your 3wire that were not used to bring either your power, sl, or neutral over to the other box.


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## knowledge29 (Nov 6, 2010)

Line on one end load at the other end. 4 way in between if needed.


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## 480sparky (Sep 20, 2007)

knowledge29 said:


> Line on one end load at the other end. 4 way in between if needed.



Well, that's ONE way. How about both the line and load at the 4-way in the middle? :whistling2:


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## Error (Feb 12, 2014)

Be organized and label what the wires are with a sharpie inside the box just incase you are not the one doing the finishing.









Keep the wiring nice and clean incase you have to troubleshoot


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## Hmacanada (Jan 16, 2014)

Error said:


> Be organized and label what the wires are with a sharpie inside the box just incase you are not the one doing the finishing. Keep the wiring nice and clean incase you have to troubleshoot


I usually twist the travellers together then strip the common and twist in the opposite direction for quick id.
But I am the only one finishing my work too!


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## 480sparky (Sep 20, 2007)

Hmacanada said:


> I usually twist the travellers together then strip the common and twist in the opposite direction for quick id.
> But I am the only one finishing my work too!


I wrap the common around the ground and travelers.


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## Chrisibew440 (Sep 13, 2013)

Error said:


> View attachment 35516
> 
> 
> Be organized and label what the wires are with a sharpie inside the box just incase you are not the one doing the finishing.
> ...


24 wires plus yokes. Whoa. Stuffed.


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## Error (Feb 12, 2014)

Chrisibew440 said:


> 24 wires plus yokes. Whoa. Stuffed.











19 wires 3 switches and two splices I think I JUST made box fill


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## LGLS (Nov 10, 2007)

Error said:


> View attachment 35519
> 
> 
> 19 wires 3 switches and two splices I think I JUST made box fill


And the ground.

Waitaminute...

For calculations I thought you only count 2 travelers as one conductor, since both cannot be carrying current? :whistling2:


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## Chrisibew440 (Sep 13, 2013)

IslandGuy said:


> And the ground.
> 
> Waitaminute...
> 
> For calculations I thought you only count 2 travelers as one conductor, since both cannot be carrying current? :whistling2:


I don't know how the Canadians do it. But box fill is box fill for us regardless of what it's doing.


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## Chrisibew440 (Sep 13, 2013)

Error said:


> View attachment 35519
> 
> 
> 19 wires 3 switches and two splices I think I JUST made box fill


I'm just rattling your cage. It looks good and I know it will be fine. One question though. Why go with the metal box? Especially that style. A plastic box would be deeper right off the bat.


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## Error (Feb 12, 2014)

Chrisibew440 said:


> I'm just rattling your cage. It looks good and I know it will be fine. One question though. Why go with the metal box? Especially that style. A plastic box would be deeper right off the bat.


I never do wire counts on ganged boxes so I thought I'd make sure. Yah I'm not sure why nadians use metal and mercans plastic.


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## Error (Feb 12, 2014)

Chrisibew440 said:


> I don't know how the Canadians do it. But box fill is box fill for us regardless of what it's doing.


This guys doing to rattling haha


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## Error (Feb 12, 2014)

Error said:


> This guys doing to rattling haha


Sorry directed at island-guy

Non Insulated conductors don't count towards box fill. Current carrying conductors has nothing to do with box fill either


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## Aegis (Mar 18, 2011)

480sparky said:


> Well, that's ONE way. How about both the line and load at the 4-way in the middle? :whistling2:


Did that once in a deep 4x4. I would say it's the most complicated setup for 3-ways and a 4-way if you don't know what your doing. To the OP, don't try this first.


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## 480sparky (Sep 20, 2007)

Aegis said:


> ....... I would say it's the most complicated setup for 3-ways and a 4-way if you don't know what your doing.......



Nah. Feeding power to the light first is.


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