"3 way" switch

[bsh]

Can anyone tell me where the name "3 way" switch came from? I know it is a single pole double throw switch. I believe they are called "2 way" switches in some other countries.

 

[roger3829]

3 screws means 3-way

4 screws means 4-way

 

[480sparky]

From a 1921 Arrow-Hart catalog:

Notice the top right wiring diagram. The text says 'point', but the diagram says 'way'. Maybe back in those days the terms were used interchageably, and 'way' eventually won out.

3 screws means 3-way

What about SPST Center-Off?

4 screws means 4-way

What about DPST? SPTT?

 

[charlie b]

I think of the word "way" in the context of "roadway." Consider a road that diverges into two roads at a "three way intersection." The word "way," in the phrase "three way intersection," does not refer to what is happening at the intersection itself (i.e., internal to the 3-way switch), but rather to the one way you came from and the two ways you could go to.

 

[BryanMD]

and then there is the idea that 3 way and 4 way (and 10 way ftm) is about the number of boxes/connection points in the circuit.

 

[al hildenbrand]

From a 1921 Arrow-Hart catalog:

The text says 'point', but the diagram says 'way'. Maybe back in those days the terms were used interchageably, and 'way' eventually won out.

I also note, and like, the hot and neutral being labeled as "main".

Interesting stuff, Ken!

 

[LarryFine]

What about SPST Center-Off?

What about DPST? SPTT?

Oh, stop it! grin

 

[benaround]

I know it is a single pole double throw switch.

bsh,

Only if you throw it twice!!

 

[newservice]

I like the 3 way intersection explanation. :roll:

 

[highvolts582]

ha

ha

My teacher used to offer a reward to the student who could make 2 single pole switches work like a 3 way. Yes people tried. no not me. Thanks Mr C. from jackson voc.

 

[LarryFine]

My teacher used to offer a reward to the student who could make 2 single pole switches work like a 3 way. Yes people tried. no not me. Thanks Mr C. from jackson voc.

Call Mr. C. and tell him you can do it if you turn one switch upside down and fashion a handle-tie so they operate together.

Connect one terminal of each switch together and use this as your common, and the remaining terminals are your travelers.

 

[480sparky]

Personally, I think it's a throw-back to the old knife switches. A SPDT can be used as a 3-way, but with a center off.

So you have 3 'ways' the switch could be positioned.... power between the common and terminal 1, power between the common and terminal 2, and off.

 

[PetrosA]

Maybe from there being three ways to turn the light out? One switch, the other switch or the pullchain