First, I wish I had been aware of this forum before retirement. It would have been a real asset to solve many IT problems.
Oh well... my problems are more mundane these days. But, here's my current dilemma: I'm doing a little household renovation.
I need to add lighting at the bottom of my basement steps which are currently lit from the top of the stairs with a 3-way switch
arrangement (switches at top and bottom of stairs). This normally wouldn't confound me; but drywall does. That is, the power
source runs through the attic to the existing light. The travelers then run to the first 3-way switch at the top of the stairs and then to
the 3-way at the bottom (where I want to add new lighting). The source, existing light, and first switch are all behind drywall. The
only accessible box (and switch) is the lower one (which only contains the travellers; no neutral). I'm a computer guy not an electrician
so have mercy on me. Short of ripping out the drywall is there a simple trick electricians use to get around this problem? I can picture
powering the lower level light via a separate slave circuit if the switching could be triggered somehow at the lower switch. I hope I'm
just being "thick as a brick" here I loathe drywall work. I'll try uploading a circuit drawing.

 

Below is a typical 3 way switch configuration which mimics your drawing.


If neutral was not run down and through the lower level switch box there has to be a neutral at the light in the basement. Typically the neutral is run through the box on the lamp side but not always. Normally just in and out using a wire nut. Lacking that there should be a neutral at the light location. There has to be or the light would never light. Would getting neutral at the light be a problem?

Ron

 

something like this

 

Below is a typical 3 way switch configuration which mimics your drawing.
View attachment 137131

If neutral was not run down and through the lower level switch box there has to be a neutral at the light in the basement. Typically the neutral is run through the box on the lamp side but not always. Normally just in and out using a wire nut. Lacking that there should be a neutral at the light location. There has to be or the light would never light. Would getting neutral at the light be a problem?

Ron

Thanks for the reply. Power (hot and neutral) enters from the attic into the existing light (at the top of the stairs near the first switch). The hot (black) source lead in the light box is wire nut tied to the white running down to the first switch (just as in my attached drawing). Both the light box and 1st switch are drywall enclosed. The only thing I have ready access to is the second 3-way switch (with no neutral) on the lower level. My problem is adding a second new load (i.e. light) on the lower level (near the second switch). Hopefully, this is clear. Yes, getting neutral for the new light is a problem as it is buried in drywall at the first, existing light.

View attachment 137132 something like this

Yup... and the only part of the circuit accessible is the right hand switch in your diagram. No neutral, no joy. But there is current flowing
thru that switch when both switches select the same traveller. Hence, my thought that if current flow were sensed there then a separate
switched circuit could activate the new lower level light. Real Rube Goldberg, I know. But, electricians must run into this problem. How do they solve it??????

 

But, electricians must run into this problem. How do they solve it??????

By going into the drywall.
How will you run the wire to your new lamp if you don't break into the drywall?

 

Why not run a neutral wire from the breaker panel to one side of the fixture and then a hot wire from the bottom switch to the other side of it? Otherwise, couldn't you simply wire the fixture using just a "hot leg" from the switch and then run a separate ground wire directly to earth?

By the way, I am not an electrician so please take my suggestions with a keg of salt!

 

Why not run a neutral wire from the breaker panel to one side of the fixture and then a hot wire from the bottom switch to the other side of it? Otherwise, couldn't you simply wire the fixture using just a "hot leg" from the switch and then run a separate ground wire directly to earth?

By the way, I am not an electrician so please take my suggestions with a keg of salt!

Thanks... I actually thought about that, but realized it probably violates a kazillion electrical codes and you end up running the lights serially rather than in parallel. But then again I really, really hate drywall work so who knows????

 

Thanks for the reply. Power (hot and neutral) enters from the attic into the existing light (at the top of the stairs near the first switch). The hot (black) source lead in the light box is wire nut tied to the white running down to the first switch (just as in my attached drawing). Both the light box and 1st switch are drywall enclosed. The only thing I have ready access to is the second 3-way switch (with no neutral) on the lower level. My problem is adding a second new load (i.e. light) on the lower level (near the second switch). Hopefully, this is clear. Yes, getting neutral for the new light is a problem as it is buried in drywall at the first, existing light.

I hate this part. Yeah, the only neutral will be at the existing lamp unfortunately. Short of running a new neutral and busting out some drywall there is no easy way around something like this. Whenever I run something like this I always use AWG 12 - 3 and include a neutral just so someone in the future isn't cursing me. Unless you can get the neutral at the light and run it to the new added light there is no really easy way around things.

Ron

 

By going into the drywall.
How will you run the wire to your new lamp if you don't break into the drywall?

Thanks for your reply. Actually, the new lamp could be powered on a separate circuit. The only thing required is a
switch which activates when current flow is sensed through the lower existing 3-way. Not being an electrician I just
thought I'd ask the question. Ya never know; there might be a common fix. But, you are probably right. What was
going to be a three hour wiring job is morphing into a week long slog of drywall removal, re-installation, mudding,
sanding, and painting. No end of fun. Seems to me that $10 of electronics could alleviate all that pain. Whatcha think?

FWIW Phenix Controls 9993A would probably do the trick. In an industrial setting I wouldn't hesitate to give it a try.
But, in a residential application, code is code and insurance people are a skeptical lot. A bit more research is definitely
in order. Any comments?

 

Actually, the new lamp could be powered on a separate circuit.

That's fine.
But how will you get the power to the lamp without doing drywall?

Edit: Perhaps a 4-Way X10 type remote control switch could work for you, such as this.

 

My coin: I was using this diagram for tens of years without of any problems. And then Europe invented miniature incandescent lamps those spiral type. I installed one object where on that three pole switcher stayed some 10 lamps for 23W each. What is that, just ONE Ampere, nothing. But after one day the client comes with a claim, full short and burn. Okay, I changed the switchers, checked wires, checked that any position is good, no mistakes. After three days a claim again. I change the switchers to the new again, check all the lamp currents at switch-on and off regimes, monitored the total current in switching time, all is okay except that after day is the claim again. At last I changed the cabling, switchers, lamp patrons, anything. After the two days the claim again. Oh-my-God!
And then I decided to make a dark shade and switch then. As at the switch-on as switch-off INTO the switcher there was looong looong thick arc filling the volume between ALL THREE contacts into the switcher. The lamp electronics use the high frequency oscillator, and RF arc is very ionizable. Thus, if one have just a one lamp, then probably risk is smaller, but as soon there stays larger current, the carbonization of switcher is imminent. Solution - I changed the system to the very old russian switchers. If modern European (read Polish) has spark gap about 1/3 mm thick, then russian has 6 mm the way out and that is too much for even RF spark.
Ah, yes, I used this circuit little bit modified, the bi-line has permanent 220V between both branches, but lamp is between jumping polusses of switcher. PROBABLY the problem would be less acute if I use a circuit like in the Reloadron. Yet then I need one more wire in the cable, however it would cost much less as I spend to get this lesson of RF current in lamps.

 

Borrowing a neutral from another circuit will work but is a code violation. By using a neutral from another circuit you have essentially made it a "multi wire circuit" which requires the circuits to be on opposite phases, and the circuit breaker handles to be tied together (double pole breaker"
which means they must be adjacent to each other. If you can meet that criteria then it would be legal.
The reason for connecting the circuit breakers is so that when working on one circuit, with power off , the other phase cannot back track through the neutral and zap you. Incidentally 2017 code now mandates that you must have a neutral in all switch locations, whether you use it or not ..
edit: this applies to US codes, possibly others.

 

How long is the flight of stairs?
I have had to do the same thing. You don't have to rip up all the drywall. Just cut rectangular holes strategically located so that you can run new cable from top to bottom. When you're finished, replace the drywall pieces, patch and paint. It's not that hard to do.

 

That's fine.
But how will you get the power to the lamp without doing drywall?

Edit: Perhaps a 4-Way X10 type remote control switch could work for you, such as this.

Hmmm... I played around with X10 when it was all the rage (about 20 years ago). I gotta take another look.
So thanks, that's a good lead (and largely UL approved). As for the drywall, the lower switch is in a partially
finished basement, The 12-3 traveler wire is completely exposed in the unfinished portion and everything is
open all the way back to the breaker box. There is no drywall to deal with; only open wall cavities and a drop
ceiling.

My coin: I was using this diagram for tens of years without of any problems. And then Europe invented miniature incandescent lamps those spiral type. I installed one object where on that three pole switcher stayed some 10 lamps for 23W each. What is that, just ONE Ampere, nothing. But after one day the client comes with a claim, full short and burn. Okay, I changed the switchers, checked wires, checked that any position is good, no mistakes. After three days a claim again. I change the switchers to the new again, check all the lamp currents at switch-on and off regimes, monitored the total current in switching time, all is okay except that after day is the claim again. At last I changed the cabling, switchers, lamp patrons, anything. After the two days the claim again. Oh-my-God!
And then I decided to make a dark shade and switch then. As at the switch-on as switch-off INTO the switcher there was looong looong thick arc filling the volume between ALL THREE contacts into the switcher. The lamp electronics use the high frequency oscillator, and RF arc is very ionizable. Thus, if one have just a one lamp, then probably risk is smaller, but as soon there stays larger current, the carbonization of switcher is imminent. Solution - I changed the system to the very old russian switchers. If modern European (read Polish) has spark gap about 1/3 mm thick, then russian has 6 mm the way out and that is too much for even RF spark.
Ah, yes, I used this circuit little bit modified, the bi-line has permanent 220V between both branches, but lamp is between jumping polusses of switcher. PROBABLY the problem would be less acute if I use a circuit like in the Reloadron. Yet then I need one more wire in the cable, however it would cost much less as I spend to get this lesson of RF current in lamps.

Good cautionary story... I had a similar experience when adding a front end PC to a PLC controlled milling machine. The PC periodically
went south for no apparent reason. Turns out the RF, current surges, etc. from the mechanical relays proved to be too much for the delicate
little PC. A Faraday cage around the PC board and swapping mechanical for optical switching put the project back on track. Problems like
that can keep you up at night.

Borrowing a neutral from another circuit will work but is a code violation. By using a neutral from another circuit you have essentially made it a "multi wire circuit" which requires the circuits to be on opposite phases, and the circuit breaker handles to be tied together (double pole breaker"
which means they must be adjacent to each other. If you can meet that criteria then it would be legal.
The reason for connecting the circuit breakers is so that when working on one circuit, with power off , the other phase cannot back track through the neutral and zap you. Incidentally 2017 code now mandates that you must have a neutral in all switch locations, whether you use it or not ..
edit: this applies to US codes, possibly others.

Alas, we all have to deal with legacy systems, the 2017 code makes sense. And, it's not the first time I wished the house was newer.
But, thanks for the explanation, I suspected dragging neutral from the breaker box was probably a very bad idea. You made it clear as to why
that's the case. But, even with a double pole breaker to couple the circuits, my situation would require that the lamps be wired in a serial connection. One bulb goes out; they all do. I doubt there are too many souls on the forum who remember when Xmas lights were wired that way. Hours of fun replacing one bulb at a time to find the bad one.

How long is the flight of stairs?
I have had to do the same thing. You don't have to rip up all the drywall. Just cut rectangular holes strategically located so that you can run new cable from top to bottom. When you're finished, replace the drywall pieces, patch and paint. It's not that hard to do.

Your point is well taken and it will, undoubtedly, be the final solution. But, for the record, I'll give you a little chuckle. My drywall work
is closer to drywall mud sculpture. The fine art of THIN coats escapes me. And, the resultant pile of sanding the dried mud usually leaves
a pile several feet deep. DUH... it seems we don't all have the same skills.

 

Your point is well taken and it will, undoubtedly, be the final solution. But, for the record, I'll give you a little chuckle. My drywall work
is closer to drywall mud sculpture. The fine art of THIN coats escapes me. And, the resultant pile of sanding the dried mud usually leaves
a pile several feet deep. DUH... it seems we don't all have the same skills.

Hang a picture frame over it and no one will notice.

 

We have available a Lob flex drill bit with a steering wheel: e.g. http://www.homedepot.com/p/Klein-Tools-Flexible-Drill-Bit-Kit-3-Piece-53721/203913339

Then there's cheap fiber camera's.

Drywall patching is easy to deal with.

X-10 has virually been replaced by UPB (Universal Power Bus) and Insteon. Sometimes all three can interoperate together,

One of them uses a combination of powerline and RF to communicate.

 

Hang a picture frame over it and no one will notice.

That or I could just disable the circuit. No light and no one can see the holes. Thanks everyone!

 

My drywall work
is closer to drywall mud sculpture. The fine art of THIN coats escapes me. And, the resultant pile of sanding the dried mud usually leaves
a pile several feet deep. DUH... it seems we don't all have the same skills.

Absolutely funny!

Look at Large hole repair here: http://www.popularmechanics.com/home/interior-projects/how-to/a185/easy-drywall-repair/

I've done very little drywall repair, but I was very good at it. Preparing for painting issues I used a pre-mixed stuff.
That was for dings, nails and cracks etc.

Replacing tiny sections of drywall is a bit harder. I was installing low-voltage electric and I FORGOT to check what was on the other side of the wall. Well it was an electrical box. Well, currently replaced with a low voltage cover. Full repair will be undertaken when the room gets painted again.

 

Absolutely funny!

Look at Large hole repair here: http://www.popularmechanics.com/home/interior-projects/how-to/a185/easy-drywall-repair/

I've done very little drywall repair, but I was very good at it. Preparing for painting issues I used a pre-mixed stuff.
That was for dings, nails and cracks etc.

Replacing tiny sections of drywall is a bit harder. I was installing low-voltage electric and I FORGOT to check what was on the other side of the wall. Well it was an electrical box. Well, currently replaced with a low voltage cover. Full repair will be undertaken when the room gets painted again.

I feel your pain. In a previous residence I actually encountered a completely buried junction box. My wife still claims to have
increased her vocabulary by least 35 words that day.

 

Dry wall is why God gave me friends who are actually good at it. Dry wall and painting just are not among things I like doing or are good at. Running new electric, yes. Currently nearing completion of a garage and as soon as it is finished I'll run the electric before insulation and dry wall goes in. As we have gone through this house ripping old walls and insulation out I have replaced all the old knob and tube wiring. Room by room and square foot by square foot. Amazing what we found in the walls and more amazing the place never burned down.

As of the NEC 2011 Article 404.2 requires a neutral in all switch boxes. The logic here is more and more electronic devices are being used in switch boxes with lighting sensors, occupancy control sensors and similar which require a neutral. What people started doing was using the Ground wire as a neutral which is a bad. My book is a NEC 2008 which does not list it as a requirement but every three years the code is updated and the 2011 NEC covers it.

Knob and Tube


It's always easy before the walls are done.

Ron