Need 3-way sw help

[RonP]

Need some help or ideas. I have a few kids in my class that just don't get it when it comes to 3way switches. I have tried a couple different methods to explain this but have had no luck. Any ideas or methods. thanks

 

[jimport]

I was one of those kids. Draw the circuit out on paper and show them how the switch internally makes the connection to each traveller. Now flip one of the switchesso they can see it change the flow across the traveller wire.

 

[charlie b]

I think that a well designed (translate: "Simple") picture should be able to tell the whole story. Can you show us (or perhaps describe to us) what pictures you have tried to use?

Also, have you tried the Internet? Here is one site I found. Please note that you have to keep hitting "Next," in order to see the entire discussion.
http://home.howstuffworks.com/three-way1.htm

 

[LawnGuyLandSparky]

Sometimes using double-throw knife switches works. When you can physically see how the circuit is being completed or interrupted - it can help. Just be sure to explain that with ordinary 3-way snap switches, there is no center-off position.

 

[RonP]

The training books we use are from the" CONTREN Learning Series" it has some basic diagrams that I put on the board as a power point presentation. That did it for the bulk of the students however during lab some students still have a problem with the travelers. I showed them a few times in a lab setting and on the board how travelers work.(with basic diagrams) I guess it is going to take repetition to make it stick.

 

[RonP]

Thank you for all the advice.

 

[Dennis Alwon]

I would get a battery, a light that will work with the battery, 2 - 3way switches, voltmeter, etc. Hands on--- hook it up and make it work---

Test them by moving the power source etc.

 

[George Stolz]

Personify the two switches. Name the travellers, black and red.

To make it amusing, take the students in question, and stand them up side by side, and call them the two switches. Explain that if the first switch says "Black" and the second switch says "Black", then they agree, so the light comes on.

If one says "Black" and the other says "Red" then the light is off.

Then explain that a fourway is just a sloppy messenger between them that either tells the truth or lies about what the first switch is saying.

Then go back to the boring pictures.

 

[jaylectricity]

Personify the two switches. Name the travellers, black and red.

To make it amusing, take the students in question, and stand them up side by side, and call them the two switches. Explain that if the first switch says "Black" and the second switch says "Black", then they agree, so the light comes on.

If one says "Black" and the other says "Red" then the light is off.

Then explain that a fourway is just a sloppy messenger between them that either tells the truth or lies about what the first switch is saying.

Then go back to the boring pictures.

Haha, that kills me. It just might work. I guess I'll give you one of these: :grin: or two

 

[tallgirl]

Sometimes using double-throw knife switches works. When you can physically see how the circuit is being completed or interrupted - it can help.

These guys sound a bit like me -- I learn a lot better when I do things with my hands than when an instructor tells me something. Drawing pictures helps, but for me, nothing beats hands-on work.

I'd let the students wire up their own 3- and 4-way switches using knife switches, batteries, etc.

The best teaching approaches bring all three styles of learning together -- seeing, hearing and doing. If you have otherwise intelligent students who are having problems grasping what you're teaching, it could be that you're missing out on one of those three.

Just be sure to explain that with ordinary 3-way snap switches, there is no center-off position.

Then how come when I race out of the house in the morning and don't flip the switch all the way, it stays in the middle and I wind up confused when flipping the other switches doesn't turn the light on? Hmmmmmm????

 

[LawnGuyLandSparky]

Then how come when I race out of the house in the morning and don't flip the switch all the way, it stays in the middle and I wind up confused when flipping the other switches doesn't turn the light on? Hmmmmmm????

If you're racing out of the house in the morning it's because you're burning the candle at both ends, not allowing yourself enough time!

As for you exceptional 3-way switch, it lacks a comprehensive residential maintainence program...

 

[tallgirl]

If you're racing out of the house in the morning it's because you're burning the candle at both ends, not allowing yourself enough time!

Heh. I take the candle, chop it into 2" pieces, cut the wax away from the wick, and light THOSE ends as well. Burning the candle at both ends is for serious under-achievers and general slackers.

As for you exceptional 3-way switch, it lacks a comprehensive residential maintainence program...

Right, I have time for a comprehensive residential maintenance program when I don't have time to turn the stupid things off properly.

 

[Brady Electric]

need 3 way sw help

need 3 way sw help

Just remember on a 3 way sw at one end you need the sw leg and the other end you need a hot then travellers from one sw to another. You can run the sw leg and hot at the same end and run 3 wire between sw's and at the other end tie the black of the 3 way to the black of the sw leg and use the wt and red as travelers but tape the wt wire either blk or red. At the end the 3 wire goes I use the blk on the dark screw and the red above it and the wt marked blk or red on the othe side. Hope this helps and doesn't confuse you. Semper Fi

 

[tallgirl]

Just remember on a 3 way sw at one end you need the sw leg and the other end you need a hot then travellers from one sw to another. You can run the sw leg and hot at the same end and run 3 wire between sw's and at the other end tie the black of the 3 way to the black of the sw leg and use the wt and red as travelers but tape the wt wire either blk or red. At the end the 3 wire goes I use the blk on the dark screw and the red above it and the wt marked blk or red on the othe side. Hope this helps and doesn't confuse you. Semper Fi

Okay, maybe I'm dense.

When I wire 3-ways and 4-ways, I always use black and red for travellers and white for the neutral.

Why the heck would you use white for a traveller when red and black are perfectly good colors? Or are you talking about wiring a dead-end 3-way? Personally, I try to avoid dead-ends because I hate the box fill that comes from doing it that way.

 

[Dennis Alwon]

Okay, maybe I'm dense.

I won't get into that one

You can run the sw leg and hot at the same end and run 3 wire between sw's and at the other end tie the black of the 3 way to the black of the sw leg and use the wt and red as travelers but tape the wt wire either blk or red.

I think that says he is wiring as a dead end. He also said "You can", not necessarily his method.

There are times when it is a whole lot easier to have the 3 way as a dead end. I try not to wire that way but there is no problem doing it

 

[Cavie]

When I teach 3/w's, I draw out the hot wires and forget about neutrals and colors. Draw a one line diagram using two sets of 3 dots and show the switch connections. If you try to include colors they will not grasp the concept of changing colors for the travlers for various 3way instalations.

 

[tallgirl]

I won't get into that one

Discretion is the better part of valour

I think that says he is wiring as a dead end. He also said "You can", not necessarily his method.

There are times when it is a whole lot easier to have the 3 way as a dead end. I try not to wire that way but there is no problem doing it

I think 3-ways are definitely one of those personal taste things. After some unpleasant experiences with other people's wiring, I stopped my more creative approaches to wiring 3-ways, some of which were horrible.

 

[quogueelectric]

3 way switching

3 way switching

set up a simple board project and use old work data boxes then try to add a 4 way switch at the feed end only using a 3 wire to the new 3rd location.

 

[George Stolz]

After some unpleasant experiences with other people's wiring, I stopped my more creative approaches to wiring 3-ways, some of which were horrible.

Hear! Hear!

I still have a bag of tricks, but may it collect dust. Keep It Simple Stupid, all the way.

 

[ptonsparky]

When doing old work, creative can be mandatory and educational, but if you can KISS is a the way to go.

On romex jobs we always use white as a traveler. Always dead end a 3 way, and only use a three wire between the sitches. Part of KISS.