# 3 way and 4 way switches



## ReedELC101 (Aug 10, 2010)

Hi, In my tech school we have an upcoming lap concerning 3 way and 4 way switches. I was wondering what the difference is between the 2. 
thank you, Kyle Reed


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## doubleoh7 (Dec 5, 2009)

That is about the simplest of questions to ask. I see in your porfile that you are in school. I assume that you are just starting. Introduce yourself a little and give us more info on your backround. Welome aboard!


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## Big City Electrician (Jul 5, 2010)

3 way switches a single pole, double throw, 4 way switches are used in the center of the travelers to redirect the current flow from one traveler to the other.


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## TheRick (Apr 13, 2008)

ReedELC101 said:


> Hi, In my tech school we have an upcoming lap concerning 3 way and 4 way switches. I was wondering what the difference is between the 2.
> thank you, Kyle Reed


3-way and 4-way switches are used to switch loads from multiple locations, 3-ways can be used for 2 locations, and you would add 4-ways for 3 or more switch locations.


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## Magnettica (Jan 23, 2007)

A 4-way switch break apart the travelers in a 3-way circuit. 

3-wire in, 3-wire out, splice together both commons.


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## McClary’s Electrical (Feb 21, 2009)

Magnettica said:


> A 4-way switch break apart the travelers in a 3-way circuit.
> 
> 3-wire in, 3-wire out, splice together both commons.


 

Are you calling the neutral a common?

If so, what do you call the wire you put on the black screw?


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## doubleoh7 (Dec 5, 2009)

mcclary's electrical said:


> Are you calling the neutral a common?
> 
> If so, what do you call the wire you put on the black screw?


Traveller


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## McClary’s Electrical (Feb 21, 2009)

doubleoh7 said:


> Traveller


 

I'd like to see that work


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## MF Dagger (Dec 24, 2007)

black screw is common on a three way. In a four way box the spare wire could either be coming off the common of a three way and feeding through or the neutral feeding through, all depends.


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## Speedy Petey (Jan 10, 2007)

I absolutely HATE the word common!! In any context. 
This word has caused so much confusion over the eyars, then they go an label the black screw on a 3-way "common". WHY???


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## Speedy Petey (Jan 10, 2007)

Big City Electrician said:


>


With two switches they are both 3-ways. Any more switches placed in the middle of the switching circuit are ALL 4-ways. 
That is the quick summary. 
They could just as easily be called "end switches" and "middle switches". It would mean the same thing.


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## MF Dagger (Dec 24, 2007)

Speedy Petey said:


> I absolutely HATE the word common!! In any context.
> This word has caused so much confusion over the eyars, then they go an label the black screw on a 3-way "common". WHY???


Because it's common to both positions the switch is in.


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## Speedy Petey (Jan 10, 2007)

Coloring it black was good enough IMO. :thumbsup:


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## doubleoh7 (Dec 5, 2009)

I don't do it, but I've heard a lot of guys call the nuetral a common. Yes, it does get confusing.


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## mattsilkwood (Sep 21, 2008)

Power in on one common, power out on the other.


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## Big City Electrician (Jul 5, 2010)

Never seems to fail that when I install 3 way switches in a home, the homeowner complains that one of the switches is "upside down".


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## ampman (Apr 2, 2009)

why didn't you ask about a lighted two way switch


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## Mr. Sparkle (Jan 27, 2009)

Big City Electrician said:


> Never seems to fail that when I install 3 way switches in a home, the homeowner complains that one of the switches is "upside down".


That right there tells you either:

A: They lived in a cave until now.

or 

B: They are stupid.


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## BuzzKill (Oct 27, 2008)

Speedy Petey said:


> I absolutely HATE the word common!! In any context.
> This word has caused so much confusion over the eyars, then they go an label the black screw on a 3-way "common". WHY???


yeah I know sometimes it seems to mean both an N and a hot....


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## TheRick (Apr 13, 2008)

Mr. Sparkle said:


> That right there tells you either:
> 
> A: They lived in a cave until now.
> 
> ...


 
You forgot;

C: Both


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## AussieApprentice (Aug 16, 2008)

Big City Electrician said:


> Never seems to fail that when I install 3 way switches in a home, the homeowner complains that one of the switches is "upside down".


Over here up position is normally off. In multiple position switching we set it up so that if all switches are in the up position, the circuit is off.

The reasoning is that if there is no power supply, the lights can be left off by turning all switches to the off position. Then when the power is restored the lights will not come on.


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## Mr. Sparkle (Jan 27, 2009)

TheRick said:


> You forgot;
> 
> C: Both


Sorry I was preoccupied with this problem I am having with this light switch in one of my bedrooms I cant figure out what it does....and it is the strangest thing because I am always having to reprogram the VCR in the same room.....must be faulty wiring in there, I'll look into it deeper someday.....but I mean you know how it is......after doing electrical work all day the last thing I want to do when I get home is more electrical work .


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## TheRick (Apr 13, 2008)

Mr. Sparkle said:


> Sorry I was preoccupied with this problem I am having with this light switch in one of my bedrooms I cant figure out what it does....and it is the strangest thing because I am always having to reprogram the VCR in the same room.....must be faulty wiring in there, I'll look into it deeper someday.....but I mean you know how it is......after doing electrical work all day the last thing I want to do when I get home is more electrical work .


HAHAHA :laughing: :laughing: :laughing:

LMFAO!


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## TOOL_5150 (Aug 27, 2007)

The best way to remember that type of circuit is: a 3 way is derived from "3 point" and 4 way meaning "4 point" when talking about the screws on the switch. 

You always have to have [2] 3 ways in order for the circuit to work, and you can add ANY amount of 4 ways between your [2] 3 ways. you will always have 2 travelers, and if you split them, you have 4 wires - 4 points, to go to your 4 way switches. 

The brass screws are always your travelers, and the black screw is always your common. 

SO the circuit can look like this:

line---[3Way]===Travelers===[3Way]---Line

or...

line---[3Way]===Travelers===[4Way]===Travelers===[3Way]---Line

The grounded and grounding conductors were omitted for simplicity.

Have fun with your 3 ways and 4 ways!

~Matt


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