4-way switching

[CoolWill]

But on all of them, regardless of the screw orientation, the black screws are one set of travelers and the brass screws are the other.

 

[LarryFine]

Some 4 ways wire differently than others. On some the travelers are on the sides and others they are across from each other.

See post #12.

 

[Strathead]

I wired in a huge house for a gadget nut . House had 5 separate entrances and several cross over hallways or walkways. Ended up with over a dozen four way switches. The great electrician working with me never wired in a four way switch so showed him how but he still wired some wrong. I always found it easier to wire in or replace four way switches if they used a NM cable from or to the three way switches or in cases of more then one four way. Customer asked for just two switches to turn on outdoor flood lights but added three four ways to be able to turn lights on at any of the five entrances and next to his bed. Like another person stated four way switches are installed between two three way switches. We had a sparky who.loved pulling pranks so I placed a Hubbell two pole switches in the boxes that had Hubbell four way switches. Had the apprentice ask him if he needed any help replacing them . Nope. After he pulled out his hair for awhile we had the apprentice quickly change them.out and tell him he only had to move two wires in each four way switch. My dad had me wire in a four way switch to reverse trains when I was maybe 10 years old.

As long as they use 14-3 or 12-3 romex.

 

[Strathead]

That's true logically (at a schematic level), but once you introduce physical enclosures, there are multiple ways to route the cables.

Say we have two switch locations (initially considered equivalent for counting purposes) and one lighting location, and we're going to wire it up without power passing through to further loads, and without surplus cables. Then we can either bring power to the light or to a switch.

If we bring the power to the light, then we need a cable from the light to a switch (they are equivalent, so only one choice here). The other switch can connect to the light or to the switch already connected. So 2 possibilities here.

If we bring power to a switch, then one option is connect from there to the light. The final switch can connect either to the switch with power or to the light. So 2 possibilities here.

Or with power to a switch, the other option is to go directly to the other switch. Then the light can be connected to either the switch with power, or to the other switch. But the configuration with the light connected to the switch with power was already counted. So just one new possibility here.

That makes a total of 5 ways to do the wiring, when you consider the switch locations initially equivalent.

Cheers, Wayne

I contend that routing the cables and wiring the switches are two different things.

 

[LarryFine]

I contend that routing the cables and wiring the switches are two different things.

Absolutely. In my house, the basement has two main rooms, connected together by a hall in the front with a downstairs front door and the stairs going up, and by a hall in the back with a bathroom and two closets, one of which now houses my home theater equipment stack.

Each room only had a switch by the door to the front hall; one was already a 3-way because of a side door to the outside. The need for a switch by each room's door to the rear hall became apparent, so I decided to convert one to 3-ways, and add a 4-way to the other one.

The 3-way was easy: run a 14-3 to the new switch, feed on the white, return on the black and red. The other room happened to have a J-box in the wring, so I only needed to interrupt the travelers and add a pair of 14-2s to the new switch location. (No, I didn't color the whites)

 

[wwhitney]

I contend that routing the cables and wiring the switches are two different things.

Depends on what you mean by "wiring". If you mean logically or schematically, sure I agree.

But for the sense of "in each switch box, choosing which wire from which cable goes to which terminal on the switch," then that's going to depend on which of the 5 ways (if I counted correctly) you've chosen to run the cables to interconnect the 3 boxes.

Cheers, Wayne

 

[garbo]

As long as they use 14-3 or 12-3 romex.

Might need 14/4 or 12/4 if a three way is the only cable entering a box. The fourth wire would have to be a grounded conductor ( ya Nuetral ) to provide power to an electronic switch.

 

[ptonsparky]

Look up the "California 3-Way" sometimes called the "coast 3-way". It could come in handy. There also an interesting, but illegal, setup called a "Carter 3-way".

I never heard of such a thing although I had encountered them with K&T wiring. Y thoughts were "How the heck did that ever work?" At the time, for me, it was easier to run new and be done

 

[Strathead]

Depends on what you mean by "wiring". If you mean logically or schematically, sure I agree.

But for the sense of "in each switch box, choosing which wire from which cable goes to which terminal on the switch," then that's going to depend on which of the 5 ways (if I counted correctly) you've chosen to run the cables to interconnect the 3 boxes.

Cheers, Wayne

Respectfully, all of your posts about this only serve to confuse the issue. Not that all of it isn't important and guys have to figure it out but, I could just as well say wiring with conduit is another way of wiring them, etc. I could be splicing in a box up above, we could have two 3 way switches for different areas in the same box, etc. I firmly believe the correct way to "teach" this is how the electricity runs and an apprentice needs to develop the skills to determine the best method of installing the wiring method over time, with supervision.

 

[wwhitney]

I firmly believe the correct way to "teach" this is how the electricity runs and an apprentice needs to develop the skills to determine the best method of installing the wiring method over time, with supervision.

I agree that it is important to understand that for a circuit with (2) 3-ways, there is just one standard way to wire it, schematic wise. And that there are multiple ways to arrange the cables between boxes, but for any of those ways, the way you actually make up each box is dictated by that schematic.

Cheers, Wayne

 

[hillbilly1]

I wired in a huge house for a gadget nut . House had 5 separate entrances and several cross over hallways or walkways. Ended up with over a dozen four way switches. The great electrician working with me never wired in a four way switch so showed him how but he still wired some wrong. I always found it easier to wire in or replace four way switches if they used a NM cable from or to the three way switches or in cases of more then one four way. Customer asked for just two switches to turn on outdoor flood lights but added three four ways to be able to turn lights on at any of the five entrances and next to his bed. Like another person stated four way switches are installed between two three way switches. We had a sparky who.loved pulling pranks so I placed a Hubbell two pole switches in the boxes that had Hubbell four way switches. Had the apprentice ask him if he needed any help replacing them . Nope. After he pulled out his hair for awhile we had the apprentice quickly change them.out and tell him he only had to move two wires in each four way switch. My dad had me wire in a four way switch to reverse trains when I was maybe 10 years old.

I had a customer that wanted to be able to switch the flood lights from every room, (8 rooms) after it was wired, he hands me motion activated floods…….

 

[infinity]

I agree that it is important to understand that for a circuit with (2) 3-ways, there is just one standard way to wire it, schematic wise. And that there are multiple ways to arrange the cables between boxes, but for any of those ways, the way you actually make up each box is dictated by that schematic.

Yup and telling the apprentice just run this or that from A to B is not going to teach him the fundamentals of wiring 3-ways. They really need to understand the way they work because in the field you may encounter any number of different wiring schemes.

I would draw this on the wall for all of my apprentices and see if they could figure out the minimum number of conductors (A and B) in the EMT raceways.

 

[garbo]

Yup and telling the apprentice just run this or that from A to B is not going to teach him the fundamentals of wiring 3-ways. They really need to understand the way they work because in the field you may encounter any number of different wiring schemes.

I would draw this on the wall for all of my apprentices and see if they could figure out the minimum number of conductors (A and B) in the EMT raceways.

View attachment 2578374

Had co-workers who where great at troubleshooting and conduit runs but would have problems with just two three way switches especially if the three way switches along with the feed had to be connected at a luminare.( A 14/3 or 12/3 cable from Luminare box to each three way switch location ) .Best was when they wired in two three way switches in parallel. .

 

[garbo]

Respectfully, all of your posts about this only serve to confuse the issue. Not that all of it isn't important and guys have to figure it out but, I could just as well say wiring with conduit is another way of wiring them, etc. I could be splicing in a box up above, we could have two 3 way switches for different areas in the same box, etc. I firmly believe the correct way to "teach" this is how the electricity runs and an apprentice needs to develop the skills to determine the best method of installing the wiring method over time, with supervision.

I was fortunate enough to attend a great Vo Tech high school where we spent 15 hours a week for three years in a modern electric shops. First year class room had a dozen 4 by 8' long three sided stalls. Each stall had its own remote circuit breaker that for safety only the teacher had a key for. First job was just running wire from a plug fuse to a porcelain lamp holder, second job to single pole switch then to lamp holder, then with lamp holder in the middle, then two three ways to a lamp holder, then a receptacle added seversl.different points and finally several four way switches. The smart reason we had a plug fuse in stalls the teacher would inspect wiring to check on correct wiring. Before he energizing power to your work he made you stand 6' away, then.power was turned in and student screwed in a light bulb. ( no light bulb yet in lamp holder we Installed ). If that light bulb lite up you had a dead short. Then teacher secured power and student screwed in a 3 amp fuse and a light bulb then after powering back up would test your wiring. This produced an easy understanding of basic wiring so most of us had no.problems wiring in start, stop, reverse push buttons with indicating lights. Got a free lunch when a coworker could not figure out how to wire in a door bell with several buttons. Told him that they are identical to start buttons that they are wired in parallel. Of course us old timers had fun back in the early 1980's at ladder logic and inputs & outputs on new equipment with computers. One computer had several internal timers. One timer input controlled affected several outputs.Don't even want to talk about marvelous state of the art modern VFD'S that have over 200 parameters.Our Danfoss outstanding tech had a one inch tick book just for programming various parameters.

 

[Eddie702]

With the requirement for a neutral at the switch boxes does that apply to every switch box for the light? So if you had 4 switches say 2 3 way and 2 4 ways do you need a neutral in every box? or just in 1 box?

When I did houses back in the day I used to run power to the light fixture and all my SP switches and 3 ways were done as switch loops. It was just easier for me to keep in my head and made it simple. I didn't always do it a simple bathroom light or light by the front door the power would go to the switch then feed the light. But on ceiling lights with multiple switches it got the switch loop usually.

 

[Little Bill]

With the requirement for a neutral at the switch boxes does that apply to every switch box for the light? So if you had 4 switches say 2 3 way and 2 4 ways do you need a neutral in every box? or just in 1 box?

Just one box if the entire area to be lit is visible from all switch locations.