3-way question

[COLDLAVA]

i have an old house i'm working on that has a pair of switch banks using only 2-wire for all the 3-ways. i think they call them "California 3-ways or lazy susan 3-ways. anyone have a diagram they can post for me on how this is accomplished?:-?

 

[JohnJ0906]

http://i125.photobucket.com/albums/p66/JohnJ0906/carter.gif

I don't know if this is what you are seeing, but here is a diagram of "Carter" 3- ways.

It could be that they are using hots and neutrals from different circuits, or even the same circuit, but not routeing the wires correctly.

edit to add - Sorry to the person who originally posted that diagram. I don't remember who did it, so I cannot give proper credit.

 

[480sparky]

Here's how it works:

 

[COLDLAVA]

thankx from Coldlava:

thankx from Coldlava:

that's the diagram i was looking for...good looking out

 

[al hildenbrand]

There's another variation of that setup that, as the OP states, only uses 2-conductor NM for the whole hookup.

It looks like this:

 

[frenchelectrican]

There one thing i hate when i did few service upgrading if you are not carefull about the lighting circuits something like what the photo show if you dealing with upstair and downstair circuit if you ever seperated it you have to watch out with the hot leg on " Californina 3 way " if you get each circuit on seprated leg or phase you will end up getting 240 [ 208 votls some case if have 208 v network] and blow the light bulb.

It did happend to me twice so far so just watch out on that oddball connection.

Merci, Marc

 

[480sparky]

There's another variation of that setup that, as the OP states, only uses 2-conductor NM for the whole hookup.

It looks like this:

Al, I took your drawing and animated it:

 

[winnie]

Note that the circuit which Al presented is _legal_ if confusing, whereas the 'Carter System' is not legal.

The Carter system switches the neutral, and may connect an ungrounded conductor to the screw shell of the lamp.

I belive that the 'Carter system' would be legal to switch (but not disconnect) a line-line load.

The circuit that Al presents only switches the ungrounded conductor.

-Jon

 

[LarryFine]

It's also very possible that the 3-ways were wired conventionally, merely using 2-conductor cable. Usually, one 2-wire cable is used for the travelers. In a separate cable, hot is at one switch, the load at the other, and the white is sometimes not used.

It's not hard to determine how it was originally wired. Disconnect at least 2 wires at each switch (noting connections) (or test with switch in both positions) and test for a single hot at only one switch, and whether it's on a common terminal.


P.S. We really do need a technical forum. People still read this one as "lighting."

 

[iwire]

I want to do some Al's way just to mess with my co-workers. :grin:

 

[stickboy1375]

I want to do some Al's way just to mess with my co-workers. :grin:

I bet they will really appreciate that....:grin:

 

[ItsHot]

co-workers

co-workers

I bet they will really appreciate that....:grin:

Bob wouldn't mess with co-workers. Would he?

 

[frenchelectrican]

I know there is a instering 3 and 4 way switching i am not sure if Al did draw it or someone else but it called traveling busway [ i think that is correct term ] that connection is very instering one.

Merci, Marc

 

[gndrod]

Al, I took your drawing and animated it:

AL & 480sparky,

From the looks of the physical conductor runs, maybe Bob won't need to mess with the co-workers, I think you have succeeded in messing with my brain. If the wiring is paired to the lamp, and the switched cable is paired, I believe, a loop return violation to [300.3(B)] is considered in its own right. Regardless of the switch position, the switch connections are not cancelled pairing, thus becoming an isolated non-cancelling ungrounded conductor pair cable between the switches. Maybe I am not seeing the physical pairing arrangement....? Any help straightening me out is appreciated. rbj

 

[480sparky]

AL & 480sparky,

From the looks of the physical conductor runs, maybe Bob won't need to mess with the co-workers, I think you have succeeded in messing with my brain. If the wiring is paired to the lamp, and the switched cable is paired, I believe, a loop return violation to [300.3(B)] is considered in its own right. Regardless of the switch position, the switch connections are not cancelled pairing, thus becoming an isolated non-cancelling ungrounded conductor pair cable between the switches. Maybe I am not seeing the physical pairing arrangement....? Any help straightening me out is appreciated. rbj

300.3(B) only states that both conductors must be in the same raceway or cable. And they are. It doesn't state that the neutral present (OK, technically the grounded conductor) must be used to carry the amperage...

But, good point nonetheless!

 

[480sparky]

Here, here, here, here, here, and here are links to odd-ball 3-way connections.

 

[al hildenbrand]

I think you have succeeded in messing with my brain.

:smile: Nice to know that I'm having an effect.

If the wiring is paired to the lamp, and the switched cable is paired, I believe, a loop return violation to [300.3(B)] is considered in its own right.

Upon reading the words in the Opening Post, I assumed that the wiring method is most likely nonmetallic. That invokes 300.3(B)(3). This allows the unbalancing of the currents, and the physical separating of current carrying conductors into different NM cables.

This is not a pretty picture when one examines the EMF, but it is Code compliant.

 

[ronaldrc]

I have it with fourways click the link below for a fourway interactive version.

http://home.comcast.net/~ronaldrc/wsb/1tb.htm

 

[gndrod]

300.20(b)

300.20(b)

:smile: Nice to know that I'm having an effect. Upon reading the words in the Opening Post, I assumed that the wiring method is most likely nonmetallic. That invokes 300.3(B)(3). This allows the unbalancing of the currents, and the physical separating of current carrying conductors into different NM cables.

This is not a pretty picture when one examines the EMF, but it is Code compliant.

Hi Al,

Yes it does, and it also invokes 300.20(B) that might not. Seems circuits going through metallic boxes need "holes drilled"(due to induction) and all is just conjecture to the original OP intention. I guess we are full circle on this discussion that was somewhere back 3 years ago with Karl Riley.

I agree that 300.3(B)(3) is a dumbing down of clean wiring principles in real world installation systems, unfortunately 300.20 only addresses inductive and not EMF interferences that are common and irritating. I had to mention wiring loops for most electricians don't give much thought on this and should at least have some idea about inherent "violations".(my quotes) I'll get off my soap box now. rbj

 

[electricalperson]

Here's how it works:

best diagram on this ive seen. also this system is called carter system