Advice please - 3 way light switches - I just moved into an older house

Advice please - 3 way light switches - I just moved into an older house where the light switches in the entry way seem to be terribly confused. (There are 4 switches 2/2 - porch light, coat closet, on/off hall light from upstairs, on/off same hall light from downstairs) I've replaced 3 way switches before so that's not the problem (famous last words?), however, that was in a different house. What I'd like to know is: Is there a way to test the wiring BEFORE throwing the circuit breaker power back on?
The need for a way to test it first is because the breaker box is downstairs into the basement and then to the opposite corner of the house. I worry that if the switches weren't wired right, I might see pretty sparks when I run zoom upstairs and around a corner to check on my repair job. And then have run zoom back downstairs and across to make sure the power is back off. Just the thought makes me nervous.
Any hints or ideas will be gratefully appreciated. Thank you,
Wilma Harrington
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If you are replacing one switch at a time it should be straight forward. Turn the light on and then throw the circuit breaker. This way you can tell it is off because there is no light on. Then just remove the old wires and place it on the new switch. Here is a pretty good picture of it and instructions: http://www.handymanwire.com/articles/3wayswitch.html
or
http://www.electrical-online.com/howtoarticles/3-wayswitches.htm
or
http://www.the-home-improvement-web.com/information/how-to/three-way-switch.htm
Hope that helps Pat
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tip number one: plug in a radio with a socket adapter and turn it up. it needs to be a type of radio that will go on when you turn on the power at the light switch. tip number two: use lighted handle switches. they are safer to newcomers and visitors and will tell you when they have power on them if a bulb or radio is plugged in. also handy when i am trying to figure out why i didn't replace them and test them one at a time. tip number three: read up on four way switches just in case.
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If you secure only one wire to each screw, I don't believe it's possible to short anything out. There is nothing internal in the design of a three-way switch which would cause a short. (Take a look at the schematic in komobu's link.) Secure the wires to the new switch, but let it hang out of the box where it isn't touching anything. Turn the breaker on. Then put gloves on and check the new switch to make sure it's wired correctly. If it is, turn the breaker off and install the switch in the box. Then turn the breaker back on. If your system is grounded and the new switch is hitting something, your breaker should trip.

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Make sure you understand exactly what you have there. If there are four control points, then it is most common to have two three-way switches (3 terminals on each) and two four-way switches (4 terminals on each). Each extra control point may be installed using an additional 4-way switch.
The four way switch acts as a kind of reversing switch to the two traveler wires which are terminated at each end by the three-way switches.
Three way (and four way) switches are mis-named but no-one ever bothered to change the term for a better understanding of common electrical use. A three way switch is more correctly termed a Single Pole Double Throw switch (SPDT). Why then, is it called a three way switch? Because it has three terminal screws on it?! Very strange.
Another mis-named electrical device.... The Current Tap.
Beachcomber
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On Mon, 16 Jan 2006 12:02:15 GMT, not snipped-for-privacy@xxx.yyy (Beachcomber) wrote:

I heard it was because when such a system is installed, wires are run to 3 places (for the 2 switches and the light).

A 4-way switch could be DPDT with opposite terminals connected internally. I'm not too sure of this, but have seen such for reversing a small DC motor (where run direction depends of polarity).

--
Mark Lloyd
http://notstupid.laughingsquid.com
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On Mon, 16 Jan 2006 12:02:15 GMT, not snipped-for-privacy@xxx.yyy (Beachcomber) wrote:

LOL. Good point.
'm sure whoever called it "3-way" first knew exactly how it worked. I wonder what he was thinking.
Or if maybe he said something that made more sense and the words got garbled along the way. I heard on the radio that "Ina Godda Da Veeda" was meant to be called "In the Garden of Eden". (Does anyone know if that is true?)

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mm wrote:

I've wondered about that. This site has a good answer: http://www.act-solutions.com/kingery06.htm Richard
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mm wrote:

It's 3-way because there are 3 different ways the light can be on.
S #1 "up" S #2 "Up" S #1 "up" S #2 "down" S #1 "down" S #2 "up"
or Switch #2 "
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snipped-for-privacy@yahoo.com says...

#1 "up" & #2 "up" = off. Otherwise SPST switches would work (and you coudn't turn the light both on and off from either end).

--
Keith

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A switch circut with two spdt switches has two on states, and two off states. I like them set up so the light is on whenever the two switches are in the same position.
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snipped-for-privacy@mail.uri.edu says...

Certainly, but Larry had three "on" states and only one "off" state (which could be done with parallel SPST switches). "Three-way" certainly is a curious terminology.
--
Keith

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People do it all the time with just regular SPDTs, but usually they call that a "mistake". More often, they get three offs and one on.
If there's only one off-state, then one of your switches is redundant.
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That's the way my hall came. The electrician lived in the n'hood, and silly me, I mentioned this to him** He didn't believe me.
**not so he woudl fix it. I'd already done that.
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Not entirely. You get to choose which is redundant without rewiring.
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Keith Williams wrote:

Well like this guy says: ".. it has to do with the number of "drop points" and not the number of switches in the circuit. You see back in the early days of electrical wiring, back in the days of Thomas Edison, the vocation of "electrician" was brand new. These new electricians would base their cost estimates partly on the number of "drop points" on each circuit. A drop point could be a switch, a load or any junction point. In a sense a circuit with only 1 switch and 1 load would be a "2-way". I suppose this was because the wires had to go "two different ways". A circuit with 2 switches and 1 load would be "3-way". Incidentally, a circuit with 1 switch and 2 loads would also be a 3-way, but over the years, the label of "3-way" has evolved into meaning any circuit with 2 switches in it." That explains it to me, but it still seems illogical. ....then there's "4 way". Richard
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snipped-for-privacy@lycos.com says...

I guess that's about as good of an explanation as I've heard.

I was going to bring that up but thought better. ;-)
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wrote:

This would be a logical OR (switches in parallel). Not a 3-way connection. With this S#1 "up" would make S#2 irrelevant. This does not happen with a 3-way (XOR function) where each switch is always active.

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