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

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/how...ayswitches.htm

or

http://www.the-home-improvement-web....way-switch.htm

Hope that helps
Pat

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.

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.

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" wrote in message
...
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

On Mon, 16 Jan 2006 06:03:42 -0500, "Bob" wrote:

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.


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

On Mon, 16 Jan 2006 12:02:15 GMT, (Beachcomber)
wrote:

On Mon, 16 Jan 2006 06:03:42 -0500, "Bob" wrote:

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.


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?!

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

Very
strange.


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).

Another mis-named electrical device.... The Current Tap.

Beachcomber

--
Mark Lloyd
http://notstupid.laughingsquid.com

"Democracy is two wolves and a lamb voting on what
to have for lunch. Liberty is a well armed lamb
contesting the vote." - Benjamin Franklin

On Mon, 16 Jan 2006 12:02:15 GMT, (Beachcomber)
wrote:


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.

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?)

Another mis-named electrical device.... The Current Tap.

Beachcomber



Remove NOPSAM to email me. Please let
me know if you have posted also.

mm wrote:
On Mon, 16 Jan 2006 12:02:15 GMT, (Beachcomber)
wrote:


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.

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?)

Another mis-named electrical device.... The Current Tap.

Beachcomber

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

mm wrote:
On Mon, 16 Jan 2006 12:02:15 GMT, (Beachcomber)
wrote:


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.

LOL. Good point.

'm sure whoever called it "3-way" first knew exactly how it worked. I
wonder what he was thinking.

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 "

In article . com,
says...

mm wrote:
On Mon, 16 Jan 2006 12:02:15 GMT, (Beachcomber)
wrote:


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.

LOL. Good point.

'm sure whoever called it "3-way" first knew exactly how it worked. I
wonder what he was thinking.

It's 3-way because there are 3 different ways the light can be on.

S #1 "up" S #2 "Up"

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

S #1 "up" S #2 "down"
S #1 "down" S #2 "up"



or Switch #2 "

--
Keith

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

S #1 "up" S #2 "down"
S #1 "down" S #2 "up"



or Switch #2 "



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.

In article ,
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).

S #1 "up" S #2 "down"
S #1 "down" S #2 "up"



or Switch #2 "



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.

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

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.

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.

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.

Keith Williams wrote:
In article ,
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).

S #1 "up" S #2 "down"
S #1 "down" S #2 "up"



or Switch #2 "



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.

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
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

On Mon, 16 Jan 2006 16:14:46 -0500, Goedjn wrote:


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.

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.

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.

Remove NOPSAM to email me. Please let
me know if you have posted also.

On 16 Jan 2006 11:25:38 -0800, "Larry Bud"
wrote:


mm wrote:
On Mon, 16 Jan 2006 12:02:15 GMT, (Beachcomber)
wrote:


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.

LOL. Good point.

'm sure whoever called it "3-way" first knew exactly how it worked. I
wonder what he was thinking.

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"


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.



or Switch #2 "

--
Mark Lloyd
http://notstupid.laughingsquid.com

"Democracy is two wolves and a lamb voting on what
to have for lunch. Liberty is a well armed lamb
contesting the vote." - Benjamin Franklin

On Mon, 16 Jan 2006 16:14:46 -0500, Goedjn wrote:



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.

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.

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.

Not entirely. You get to choose which is redundant without rewiring.
--
Mark Lloyd
http://notstupid.laughingsquid.com

"Democracy is two wolves and a lamb voting on what
to have for lunch. Liberty is a well armed lamb
contesting the vote." - Benjamin Franklin

In article . com,
says...

Keith Williams wrote:
In article ,
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).

S #1 "up" S #2 "down"
S #1 "down" S #2 "up"



or Switch #2 "



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.

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
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."

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

That explains it to me, but it still seems illogical.

....then there's "4 way".

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

--
Keith