“What’s a 3-way switch...?”

[romex jockey]

well..... has anyone dismantled a 3W here?

Hit it with a hammer

betcha it splits into at least 3 pieces

~S~

 

[goldstar]

My guess - a 3-way switch has 3 termination points and a 4-way has 4. Seems kind if basic but I don't think whomever invented these switches thought of it any other way IMHO.

 

[K8MHZ]

My guess - a 3-way switch has 3 termination points and a 4-way has 4. Seems kind if basic but I don't think whomever invented these switches thought of it any other way IMHO.

That's how I understand it, and it supposedly came from the number of 'ways' (highway, roadway) that went into a town.

 

[norcal]

I do believe that the Brits call them "2-way" switches.

 

[drcampbell]

... If I was wiring it today I would have something better.

Hear here. My standard wiring method for small stationary tools is a 3-pole hesitation switch, (the third pole switches the motor off) start/stop momentary pushbuttons and a seal-in relay. (large tools generally come with their own controls pre-installed)

I do believe that the Brits call them "2-way" switches.

Of course. Two friendly nations divided by a common language.

 

[kwired]

Hear here. My standard wiring method for small stationary tools is a 3-pole hesitation switch, (the third pole switches the motor off) start/stop momentary pushbuttons and a seal-in relay. (large tools generally come with their own controls pre-installed)


Of course. Two friendly nations divided by a common language.

After a few hundred years we still don't want to be like them is what it comes down to, even subconsciously we sometimes do this sort of thing.

 

[Frank DuVal]

So, in the trivial case of a standard light switch, it's a 2-way?

Of course a single pole switch is "2-Way", ON and OFF!

 

[K8MHZ]

Of course a single pole switch is "2-Way", ON and OFF!

Yes it is. But not for that reason, as I am sure you know.

 

[GoldDigger]

That's why I had a separate switch to turn the motor ON or OFF. The reversing switch was only toggled when the power switch was off. Also, when the motor was up to speed the centrifugal switch disconnected the starting winding. It wasn't foolproof, but nothing really is when running a lathe.
If I was wiring it today I would have something better.

The hesitation action switch mentioned earlier was designed for just such an application, among others.

 

[drcampbell]

Of course a single pole switch is "2-Way", ON and OFF!

"3-way" and "4-way" switches also have two positions and turn the light ON and OFF.

 

[K8MHZ]

The hesitation action switch mentioned earlier was designed for just such an application, among others.

Is a hesitation switch also called a 'make after break' switch?

 

[drcampbell]

Is a hesitation switch also called a 'make after break' switch?

Sort of. A hesitation switch will break all the contacts before making any, but that's not its primary attribute, and many make-after-break switches are not hesitation switches.

The thing that defines a hesitation switch is that when you attempt to switch it from "forward" to "reverse", a mechanical interlock will let it go only halfway, stopping in the "off" position. It will remain in the "off" position until you relax, and only then will it let you continue and switch into "reverse".

 

[kwired]

The hesitation action switch mentioned earlier was designed for just such an application, among others.

Most that are familiar with Rigid power threaders probably seen one.

In that application you probably still want to wait for the machine to come to a complete stop before switching it to the opposite direction.

 

[charlie b]

I think this is easier that some of you are making it out to be. Consider a road that runs northwards and splits into two roads. One goes NW - half left. The other goes NE - half right. Stop briefly in the intersection. You have a choice: you can go this way, or that way, or the other way. There are three paths you can choose from. In this context, the word "way" has to do with the path of travel.

The concept is similar for a 3-way switch. Some of you have said essentially the same thing. But talking to a customer in terms of terminations is harder for them to follow. Talking about roads is likely a bit easier for them to understand.

 

[kwired]

I think this is easier that some of you are making it out to be. Consider a road that runs northwards and splits into two roads. One goes NW - half left. The other goes NE - half right. Stop briefly in the intersection. You have a choice: you can go this way, or that way, or the other way. There are three paths you can choose from. In this context, the word "way" has to do with the path of travel.

The concept is similar for a 3-way switch. Some of you have said essentially the same thing. But talking to a customer in terms of terminations is harder for them to follow. Talking about roads is likely a bit easier for them to understand.

But the switch or gate in a valve only lets you go two ways at any time.

same with the 4 way except there are two incoming roads and two outgoing roads but crossover changes depending which way the switch/valve is positioned.