I have three lights A, B, C and two switches 1 and 2. How do I wire them
so switch 1 turns on/off A and B and switch 2 turns on/off B and C?
Please note that B is controlled by both switches, kind of like a 3-way
switching. Would there be any problem if both switches are on?

On 2/18/2017 8:19 PM, Chuck Jacobs wrote:
I have three lights A, B, C and two switches 1 and 2. How do I wire them so switch 1 turns on/off A and B and switch 2 turns on/off B and C? Please note that B is controlled by both switches, kind of like a 3-way switching. Would there be any problem if
both switches are on?


You could use DPST switches but I'd just put B on a pair of SPDT switches and put a and b on their own SPST switches.

On 02/18/2017 08:20 PM, Buzz Watts wrote:
On 2/18/2017 8:19 PM, Chuck Jacobs wrote:
I have three lights A, B, C and two switches 1 and 2. How do I wire
them so switch 1 turns on/off A and B and switch 2 turns on/off B and
C? Please note that B is controlled by both switches, kind of like a
3-way switching. Would there be any problem if both switches are on?


You could use DPST switches but I'd just put B on a pair of SPDT
switches and put a and b on their own SPST switches.




Nope, that would not work as a so called 3-way switch is single pole
DOUBLE throw.

To do what the OP desires would actually take two DPDT switches.

B would be a standard 3way hook up A and B would just require the spst
terminals

though such switches are very common (as a toggle switch) as a wall
switch for a house I have never seen such a thing. Probably could get
one somewhere but your average hardware store would not have
it...possibly an industrial supply house

On Sun, 19 Feb 2017 07:49:16 +0630, Chuck Jacobs
wrote:

I have three lights A, B, C and two switches 1 and 2. How do I wire them
so switch 1 turns on/off A and B and switch 2 turns on/off B and C?
Please note that B is controlled by both switches, kind of like a 3-way
switching. Would there be any problem if both switches are on?

The easy way is to put a fixture with 2 lamp holders in the B position
and wire one to A and the other to C.
If you are willing to run a lot of wire I imagine we can come up with
a way of doing it with one light in B

COrrection:
B would be a standard 3way hook up A and C would just require the spst
terminals

On 02/18/2017 08:38 PM, wrote:
On Sun, 19 Feb 2017 07:49:16 +0630, Chuck Jacobs
wrote:

I have three lights A, B, C and two switches 1 and 2. How do I wire them
so switch 1 turns on/off A and B and switch 2 turns on/off B and C?
Please note that B is controlled by both switches, kind of like a 3-way
switching. Would there be any problem if both switches are on?

The easy way is to put a fixture with 2 lamp holders in the B position
and wire one to A and the other to C.
If you are willing to run a lot of wire I imagine we can come up with
a way of doing it with one light in B




This seems to be the best solution


the one I offered would not only require a special switch I realized
after I posted that there would be no way to have all lights on or all
lights off at the same time. In other words... useless.

On 2/18/17 8:38 PM, wrote:
On Sun, 19 Feb 2017 07:49:16 +0630, Chuck Jacobs
wrote:

I have three lights A, B, C and two switches 1 and 2. How do I wire them
so switch 1 turns on/off A and B and switch 2 turns on/off B and C?
Please note that B is controlled by both switches, kind of like a 3-way
switching. Would there be any problem if both switches are on?

The easy way is to put a fixture with 2 lamp holders in the B position
and wire one to A and the other to C.
If you are willing to run a lot of wire I imagine we can come up with
a way of doing it with one light in B


Would using a dimmer switch help somehow? If, say, the OP's
end goal is
to vary the light level?

On Sunday, February 19, 2017 at 10:01:16 AM UTC-5, philo wrote:
On 02/18/2017 08:38 PM, wrote:
On Sun, 19 Feb 2017 07:49:16 +0630, Chuck Jacobs
wrote:

I have three lights A, B, C and two switches 1 and 2. How do I wire them
so switch 1 turns on/off A and B and switch 2 turns on/off B and C?
Please note that B is controlled by both switches, kind of like a 3-way
switching. Would there be any problem if both switches are on?

The easy way is to put a fixture with 2 lamp holders in the B position
and wire one to A and the other to C.
If you are willing to run a lot of wire I imagine we can come up with
a way of doing it with one light in B




This seems to be the best solution


the one I offered would not only require a special switch I realized
after I posted that there would be no way to have all lights on or all
lights off at the same time. In other words... useless.

I agree, your initial idea, I initially thought would work too.
But you wind up with a 3-way switch on one pole and essentially
a SPST on the other, so while you can control the lights, you
still can't get them to do what you want if the other switch is
in the other position. I don't see a way of doing it just
with two switches.

On 02/19/2017 10:18 AM, trader_4 wrote:
On Sunday, February 19, 2017 at 10:01:16 AM UTC-5, philo wrote:
On 02/18/2017 08:38 PM, wrote:
On Sun, 19 Feb 2017 07:49:16 +0630, Chuck Jacobs
wrote:

I have three lights A, B, C and two switches 1 and 2. How do I wire them
so switch 1 turns on/off A and B and switch 2 turns on/off B and C?
Please note that B is controlled by both switches, kind of like a 3-way
switching. Would there be any problem if both switches are on?

The easy way is to put a fixture with 2 lamp holders in the B position
and wire one to A and the other to C.
If you are willing to run a lot of wire I imagine we can come up with
a way of doing it with one light in B




This seems to be the best solution


the one I offered would not only require a special switch I realized
after I posted that there would be no way to have all lights on or all
lights off at the same time. In other words... useless.

I agree, your initial idea, I initially thought would work too.
But you wind up with a 3-way switch on one pole and essentially
a SPST on the other, so while you can control the lights, you
still can't get them to do what you want if the other switch is
in the other position. I don't see a way of doing it just
with two switches.




Yep.

Unless one wanted to use relays and design a logic circuit, the only
practical way would be to use two bulbs at location "B"

That way a three-way switch at each end could be used


Bulb A tied to B(a) Bulb C tied to B(b)

On 02/19/2017 10:32 AM, philo wrote:
On 02/19/2017 10:18 AM, trader_4 wrote:
On Sunday, February 19, 2017 at 10:01:16 AM UTC-5, philo wrote:
On 02/18/2017 08:38 PM, wrote:
On Sun, 19 Feb 2017 07:49:16 +0630, Chuck Jacobs
wrote:

I have three lights A, B, C and two switches 1 and 2. How do I wire
them
so switch 1 turns on/off A and B and switch 2 turns on/off B and C?
Please note that B is controlled by both switches, kind of like a
3-way
switching. Would there be any problem if both switches are on?

The easy way is to put a fixture with 2 lamp holders in the B position
and wire one to A and the other to C.
If you are willing to run a lot of wire I imagine we can come up with
a way of doing it with one light in B




This seems to be the best solution


the one I offered would not only require a special switch I realized
after I posted that there would be no way to have all lights on or all
lights off at the same time. In other words... useless.

I agree, your initial idea, I initially thought would work too.
But you wind up with a 3-way switch on one pole and essentially
a SPST on the other, so while you can control the lights, you
still can't get them to do what you want if the other switch is
in the other position. I don't see a way of doing it just
with two switches.




Yep.

Unless one wanted to use relays and design a logic circuit, the only
practical way would be to use two bulbs at location "B"

That way a three-way switch at each end could be used


Bulb A tied to B(a) Bulb C tied to B(b)




LOL. should have thought about that first....
No option for all off.


two switches is the way to go I think

On Sun, 19 Feb 2017 10:37:35 -0600
philo wrote:

LOL. should have thought about that first....

perfect fail record...

On 02/18/2017 08:38 PM, wrote:
On Sun, 19 Feb 2017 07:49:16 +0630, Chuck Jacobs
wrote:

I have three lights A, B, C and two switches 1 and 2. How do I wire them
so switch 1 turns on/off A and B and switch 2 turns on/off B and C?
Please note that B is controlled by both switches, kind of like a 3-way
switching. Would there be any problem if both switches are on?

The easy way is to put a fixture with 2 lamp holders in the B position
and wire one to A and the other to C.
If you are willing to run a lot of wire I imagine we can come up with
a way of doing it with one light in B


I would accomplish the same thing by using double-pole switches rather
than 2 lights at B. One pole of each switch for B, the other for A or C.

Note that neither is the same as 3-way. In one of these setups, you get
light at B if EITHER switch is on (1 OR 2). In a 3-way, you get light
only when the switches are in DIFFERENT positions (1 XOR 2).

--
Mark Lloyd
http://notstupid.us/

"All religions are founded on the fear of the many and the cleverness of
the few." -- Marie Henri Beyle (Stendhal)

On 02/18/2017 08:38 PM, philo wrote:


COrrection:
B would be a standard 3way hook up A and C would just require the spst
terminals



That would be strange. Consider what happens when you operate switch 1.
You get either:

Switch 1 turns lights A and B on/off together.

OR

Switch 1 switches between the lights (A on / B off) and (A off / B on).

Depending on the state of switch 2.

--
Mark Lloyd
http://notstupid.us/

"All religions are founded on the fear of the many and the cleverness of
the few." -- Marie Henri Beyle (Stendhal)

On 02/19/2017 09:01 AM, philo wrote:

[snip]

the one I offered would not only require a special switch I realized
after I posted that there would be no way to have all lights on or all
lights off at the same time. In other words... useless.

I may be confused about which way that is (I think double-pole
double-throw switches with one pole used as 3-way). One combination has
all 3 lights off, the others have TWO lights on. These is no combination
for ONE light on, or all on.

That is, all off, A and B on, B and C on, A and C on.

The other way has all off, A and B on, B and C on, all on.

The difference is if turning A and C on will turn B on or off.

As for B, it's the same difference as between the logic functions OR and
XOR (exclusive-or), which made this easier to understand.

--
Mark Lloyd
http://notstupid.us/

"All religions are founded on the fear of the many and the cleverness of
the few." -- Marie Henri Beyle (Stendhal)

On 02/19/2017 10:32 AM, philo wrote:

[snip]

Unless one wanted to use relays and design a logic circuit, the only
practical way would be to use two bulbs at location "B"

That way a three-way switch at each end could be used


Bulb A tied to B(a) Bulb C tied to B(b)

So now you have 4 bulbs, in 2 parallel connections. Both 3-way? Now you
have FOUR switches.

Or do you use regular switches? That might be the way I choose (although
I'd still prefer the DP switches). It's not 3-way.

--
Mark Lloyd
http://notstupid.us/

"All religions are founded on the fear of the many and the cleverness of
the few." -- Marie Henri Beyle (Stendhal)

On 19/02/2017 23:02, philo wrote:
On 02/19/2017 10:18 AM, trader_4 wrote:
On Sunday, February 19, 2017 at 10:01:16 AM UTC-5, philo wrote:
On 02/18/2017 08:38 PM, wrote:
On Sun, 19 Feb 2017 07:49:16 +0630, Chuck Jacobs
wrote:

I have three lights A, B, C and two switches 1 and 2. How do I wire
them
so switch 1 turns on/off A and B and switch 2 turns on/off B and C?
Please note that B is controlled by both switches, kind of like a
3-way
switching. Would there be any problem if both switches are on?

The easy way is to put a fixture with 2 lamp holders in the B position
and wire one to A and the other to C.
If you are willing to run a lot of wire I imagine we can come up with
a way of doing it with one light in B




This seems to be the best solution


the one I offered would not only require a special switch I realized
after I posted that there would be no way to have all lights on or all
lights off at the same time. In other words... useless.

I agree, your initial idea, I initially thought would work too.
But you wind up with a 3-way switch on one pole and essentially
a SPST on the other, so while you can control the lights, you
still can't get them to do what you want if the other switch is
in the other position. I don't see a way of doing it just
with two switches.




Yep.

Unless one wanted to use relays and design a logic circuit, the only
practical way would be to use two bulbs at location "B"

That way a three-way switch at each end could be used


Bulb A tied to B(a) Bulb C tied to B(b)

Thanks to all who replied to my question. I didn't realize this would be
so involved. I thought it was just a simple wiring problem.

If there are two bulbs at B, wouldn't two single pole switches do the
job, one for A, B(a), the other B(b), C?

On 19/02/2017 22:37, Dean Hoffman wrote:
On 2/18/17 8:38 PM, wrote:
On Sun, 19 Feb 2017 07:49:16 +0630, Chuck Jacobs
wrote:

I have three lights A, B, C and two switches 1 and 2. How do I wire them
so switch 1 turns on/off A and B and switch 2 turns on/off B and C?
Please note that B is controlled by both switches, kind of like a 3-way
switching. Would there be any problem if both switches are on?

The easy way is to put a fixture with 2 lamp holders in the B position
and wire one to A and the other to C.
If you are willing to run a lot of wire I imagine we can come up with
a way of doing it with one light in B


Would using a dimmer switch help somehow? If, say, the OP's
end goal is
to vary the light level?

Not to vary the light level. My actual situation is a little more
complex than what I have posted.

This is for bathroom. I want to have one light each above vanity, shower
stall, and commode while at the same time a common light for the whole
bathroom.

On 02/19/2017 08:19 PM, Chuck Jacobs wrote:

Bulb A tied to B(a) Bulb C tied to B(b)

Thanks to all who replied to my question. I didn't realize this would be
so involved. I thought it was just a simple wiring problem.

If there are two bulbs at B, wouldn't two single pole switches do the
job, one for A, B(a), the other B(b), C?



What made a seemingly simple question complicated was that you said you
wanted "B" controlled by two switches.



If you have two bulbs at"B" then a single pole switch indeed could
control A and B(a) and the second single pole switch could control
B(b) and C

On 02/19/2017 02:41 PM, Mark Lloyd wrote:
On 02/18/2017 08:38 PM, philo wrote:


COrrection:
B would be a standard 3way hook up A and C would just require the spst
terminals



That would be strange. Consider what happens when you operate switch 1.
You get either:

Switch 1 turns lights A and B on/off together.

OR

Switch 1 switches between the lights (A on / B off) and (A off / B on).

Depending on the state of switch 2.




Yep, after I posted solutions I realized I was wrong.


I think it may be all sorted out now

On 02/19/2017 02:58 PM, Mark Lloyd wrote:
On 02/19/2017 09:01 AM, philo wrote:

[snip]

the one I offered would not only require a special switch I realized
after I posted that there would be no way to have all lights on or all
lights off at the same time. In other words... useless.

I may be confused about which way that is (I think double-pole
double-throw switches with one pole used as 3-way). One combination has
all 3 lights off, the others have TWO lights on. These is no combination
for ONE light on, or all on.

That is, all off, A and B on, B and C on, A and C on.

The other way has all off, A and B on, B and C on, all on.

The difference is if turning A and C on will turn B on or off.

As for B, it's the same difference as between the logic functions OR and
XOR (exclusive-or), which made this easier to understand.




Yes I messed up a bit

Years ago I was good at logic and could do it again if I thought a
little harder

On Sun, 19 Feb 2017 14:37:12 -0600, Mark Lloyd
wrote:

The easy way is to put a fixture with 2 lamp holders in the B position
and wire one to A and the other to C.
If you are willing to run a lot of wire I imagine we can come up with
a way of doing it with one light in B


I would accomplish the same thing by using double-pole switches rather
than 2 lights at B. One pole of each switch for B, the other for A or C.

Note that neither is the same as 3-way. In one of these setups, you get
light at B if EITHER switch is on (1 OR 2). In a 3-way, you get light
only when the switches are in DIFFERENT positions (1 XOR 2).

You can certainly use 2 pole switches and run 2 extra wires to "B" and
"C" to avoid the parallel neutral violation. The "B" side of the
switch at "C" would be on a loop.
There are other options but it still ends up being a lot of extra
wire. That is particularly true after 2014 when a neutral is required
at each switch location

On Sunday, February 19, 2017 at 3:37:15 PM UTC-5, Mark Lloyd wrote:
On 02/18/2017 08:38 PM, wrote:
On Sun, 19 Feb 2017 07:49:16 +0630, Chuck Jacobs
wrote:

I have three lights A, B, C and two switches 1 and 2. How do I wire them
so switch 1 turns on/off A and B and switch 2 turns on/off B and C?
Please note that B is controlled by both switches, kind of like a 3-way
switching. Would there be any problem if both switches are on?

The easy way is to put a fixture with 2 lamp holders in the B position
and wire one to A and the other to C.
If you are willing to run a lot of wire I imagine we can come up with
a way of doing it with one light in B


I would accomplish the same thing by using double-pole switches rather
than 2 lights at B. One pole of each switch for B, the other for A or C.

Note that neither is the same as 3-way. In one of these setups, you get
light at B if EITHER switch is on (1 OR 2).

Which doesn't give him what he wants. The B light can be
on and not responsive to the switch in one of the two locations.
It's Philo's initial idea, which as he figured out,
doesn't work. Since he has two bulbs in the B fixture,
if he can live with one bulb for each circuit, that's the
only solution I see so far that does what he wants. That's
the one that Gfre came up with.




In a 3-way, you get light
only when the switches are in DIFFERENT positions (1 XOR 2).

--
Mark Lloyd
http://notstupid.us/

"All religions are founded on the fear of the many and the cleverness of
the few." -- Marie Henri Beyle (Stendhal)

On Mon, 20 Feb 2017 08:51:23 -0800 (PST), trader_4
wrote:

On Sunday, February 19, 2017 at 3:37:15 PM UTC-5, Mark Lloyd wrote:
On 02/18/2017 08:38 PM, wrote:
On Sun, 19 Feb 2017 07:49:16 +0630, Chuck Jacobs
wrote:

I have three lights A, B, C and two switches 1 and 2. How do I wire them
so switch 1 turns on/off A and B and switch 2 turns on/off B and C?
Please note that B is controlled by both switches, kind of like a 3-way
switching. Would there be any problem if both switches are on?

The easy way is to put a fixture with 2 lamp holders in the B position
and wire one to A and the other to C.
If you are willing to run a lot of wire I imagine we can come up with
a way of doing it with one light in B


I would accomplish the same thing by using double-pole switches rather
than 2 lights at B. One pole of each switch for B, the other for A or C.

Note that neither is the same as 3-way. In one of these setups, you get
light at B if EITHER switch is on (1 OR 2).

Which doesn't give him what he wants. The B light can be
on and not responsive to the switch in one of the two locations.
It's Philo's initial idea, which as he figured out,
doesn't work. Since he has two bulbs in the B fixture,
if he can live with one bulb for each circuit, that's the
only solution I see so far that does what he wants. That's
the one that Gfre came up with.

If you are willing to use solid state switching or "RR" series relays,
there are lots of options. Otherwise you will need 2 pole switches and
lots of wire. If the power is sourced in the "B" enclosure, the
solution is the easiest but you are still running "4 wire" to each
double pole switch to be legal in the 2014 code. (you need a neutral,
even if it is just a switch loop)