# Wiring diagram for three-way switches with pilot light



## rjniles

There a 3 way switches with small neon pilot lights that glow when the controlled light is off. The way they are wired in the switch is they are connected across the 2 travelers and use the path thru the bulb filament to find a neutral. (There is always power on one of the travelers). If your combination 3 way switches have neon pilots you could wire the same (pilot across the travelers)


----------



## rjniles

To use regular pilot lights you do need 4 wires between the switches, At the switch where the hot is not connected to the common (meaning the black of the lamp is connected), connect the pilot between the common and neutral. Use the 4th wire to run that common back to the other switch and connect pilot from the 4th wire to neutral. Lacking 4 wire cable you can run 2 two wire cables between the switches.


----------



## Stubbie

Try this to go along with rjniles explanations.....drawing is borrowed from levitons technical library


----------



## SaxTeacher

*About that neutral...*

Thanks for the replies! That diagram is just what I needed. I am almost ready to proceed but I will need one more answer:

I have a floodlight on the outside of my garage. It is currently controlled by a 2-way switch in the garage. I am adding a UF cable buried under the yard to connect it to the house. I will change the 2-way switch in the garage to be a 3-way switch, and will add a 3-way-switch-with-pilot-light in the house.

Since there is already power to the existing switch in the garage, the underground wire from garage to house will be the switch leg only. It will contain two travelers plus the common. 

BUT since the 3-way switch inside the house is going to have a pilot light, I will need a neutral there. 

The 3-way-switch-with-pilot-light is going to be located inside the house, in a 3-gang box with a couple other switches. 

So my *QUESTION *is:can I tap into the neutral wire already existing inside the box as the neutral needed to make the pilot light work? Or is that unwise/unsafe/not allowed, because the neutral already in the box is from an entirely different circuit? (The neutrals from all the circuits in the entire house DO end up all wired onto the same bar in the panel, right? So how, then, could it matter which one I use?)

Thanks again for your help!

P.S. Please note I am talking about a *PILOT LIGHT* - that is, an indicator light that lights up when the outdoor floodlights are ON. This is _not_ an illuminated switch, which would illuminate when the lights are off.


----------



## theatretch85

Using one of the neutrals from another circuit does NOT sound like a good idea. I installed some pilot light 3 way switches in a recent garage complete re-wire project and they don't need the neutral wire for the pilot light to work. The switch is only lit when the load is off (in this case its to find the switch in the dark), and it works just like rjniles said through the travelers. The current required to illuminate the pilot light is next to nothing, so it runs through the filament of the bulb. If the load is disconnected (for instance bad or removed bulb) the pilot light will not light. In thinking about this, I realize what your are looking for is a indicator that shows that the connected light on your garage is on. This would require a neutral, to make it easier and simpler, I would just install a 3-way switch that only lights up when the lights are off. Little backwards than what you want, but its a lot easier than running different wire or re-wiring the lights to pull power from the house instead of the garage.


----------



## jimmy21

what im thinking...... there would be two ways to do this, either way you would need 4 wires between the two 3-ways

method 1: Power at 3-way, switch leg at the other 3 way. You would need 2 travelers, a neutral, and a switch leg to go back to the first 3-ways pilot light

method 2: power and switchleg both at the same 3 way, dead end at the other side. You would still need 2 travelers over, a switchleg back, and because of the pilot light, you would need a neutral to operate it


----------



## Stubbie

> So my *QUESTION *is:can I tap into the neutral wire already existing inside the box as the neutral needed to make the pilot light work? Or is that unwise/unsafe/not allowed, because the neutral already in the box is from an entirely different circuit? (The neutrals from all the circuits in the entire house DO end up all wired onto the same bar in the panel, right? So how, then, could it matter which one I use?)
> 
> Thanks again for your help!
> 
> P.S. Please note I am talking about a *PILOT LIGHT* - that is, an indicator light that lights up when the outdoor floodlights are ON. This is _not_ an illuminated switch, which would illuminate when the lights are off.


I see absolutely no problem with your plan. The neutral your going to use is not a different circuit but the same branch circuit that is powering the switch loop back to the 3-way pilot light.

At the pilot light switch in the house you will need a small jumper from the switched common to the pilot light terminal.


----------



## jimmy21

you can't use a different circuits nuetral. Yes it will work, and it won't make any difference. But if you do that you can overload the nuetral. Your hot wires are on circuit breakers, limiting them to 15 or 20 amps Which would limit the nuetral to the same, unless you started using nuetrals from other circuits


----------



## SaxTeacher

Stubbie said:


> I see absolutely no problem with your plan. The neutral your going to use is not a different circuit but the same branch circuit that is powering the switch loop back to the 3-way pilot light.
> 
> At the pilot light switch in the house you will need a small jumper from the switched common to the pilot light terminal.


This sounds incorrect to me based on the wiring diagram that was provided above. Does anyone else think this is wrong? I don't want to wire it this way and have a big POP when I turn on the breaker...


----------



## theatretch85

The op has indicated that the power for these lights is coming from the garage, not the same box as this switch in question inside the house. If it were getting power at the house side, then there would be no issue here. I don't think its an issue of overloading the neutral, since it would only be powering the pilot light at one switch.


----------



## Stubbie

Where is the different circuit coming from...? He is replacing the single pole at the garage with a 3 way then cabling back to the house with 4 conductor for his pilot light 3 way switch loop. He is not adding a branch circuit just changing what he has to a 3 way. He could even keep the single pole if he wanted and add the 3 way and still be using the same neutral not a different one.


----------



## Stubbie

This is what I understand you have and using your 4 conductor cable


----------



## HouseHelper

Stubbie: I don't believe he is planning to use 4 conductor between the garage and house (see post #5)... that is why he is considering "borrowing" a neutral... a bad idea!

Best way would be to power the garage light at the house so you would have a hot and neutral from the same circuit there. The 3 conductors to the garage would be the 2 travelers and the switch leg. That makes the switch leg available at the house to connect the pilot light to.


----------



## theatretch85

Stubbie, your drawing would require a 5 wire cable to complete. It would require a Ground, Neutral, plus 3 hot wires (two travelers, plus a common); and you cant use the ground as the neutral wire. I am guessing this 4 wire cable the op has is 3 wire + ground (bare ground, white, black, red). Unless the op is running conduit the entire distance from switch box to switch box, and pulling individual wires through the only logical way to do this would be what HouseHelper and I have suggested is to power the garage light from the house side of the circuit.


----------



## Stubbie

Househelper and Theatertech85 

Yes I see what you have said and I missed the part about using a neutral in the 3-gang box at the house I also thought this garage was attached but is not and he is wanting to bury uf for the switch leg. So I am in agreement that he should just power the pilot light three way at the house and run a 3 conductor uf to the garage threeway..no issue.

So where does the 4 conductor cable he specifically stated he was using come into play if he is running a 3 conductor uf for the cable between switches?????

He did say in his first post that power was in the garage. He could, if he would like, bury the 4 conductor cable if it is long enough and rated for direct bury. If he has NM-b 4 conductor then he is out of luck (can't bury it). Color code for 4 conductor cable is usually black,red,blue,white (neutral), and bare ground.

Theatertech85

I don't always show the ground wire in my drawings. I forgot to state that the ground was not shown. So I will correct the drawing. Sometimes when I draw something in a hurry I forget that part. Cable always has an understood ground so there are 5 wires in a four conductor cable....4 conductors..... 3 hots,one neutral and a bare ground. I couldn't find an image of 4 conductor but below is 2/2 with ground the only difference is one of the whites is blue. I believe he has 4 conductor with ground because he makes a strong statement to that effect.


----------



## theatretch85

Stubbie, where did you find that wire? I have never seen that NM before! That would work, however is not rated for underground use even if it was in conduit. I have heard of 4 conductor with ground where its a bare ground white, black, red and blue, but I have never seen this NM in person before. When I completely re-wired my garage, I put in 3 sets of 3 way switches (garage main lights, garage work lights, and single pedestrian door outside light) I designed it such that it was all on the same circuit and used standard 3 conductor plus ground. However, that special NM would have been nice for the outside light, as the light is directly above the switch box, so consequently I had to run power to that box (it was originally done this way any way, just with a standard single pole switch). In case anyone is wondering "why" on 3 sets of 3way switches, outside light and work lights were getting left on, and wanted switches by the house door (in an attached garage) to shut off these other lights. Then added a pilot light 3 way by the outside door to turn on the main garage lights when walking in through the garage.


----------



## jimmy21

Stubbie said:


> Theatertech85
> 
> I don't always show the ground wire in my drawings. I forgot to state that the ground was not shown. So I will correct the drawing. Sometimes when I draw something in a hurry I forget that part. Cable always has an understood ground so there are 5 wires in a four conductor cable....4 conductors..... 3 hots,one neutral and a bare ground. I couldn't find an image of 4 conductor but below is 2/2 with ground the only difference is one of the whites is blue. I believe he has 4 conductor with ground because he makes a strong statement to that effect.




grounds are never included in diagrams. Reason being....... there would be no point. Just connect all your grounds together


----------



## Stubbie

Hi Jim

Yes that is true about drawings however in a DIY format not everyone is schooled in that regard and it becomes important to remind them of a equipment ground not being shown. 

I apologize for misreading post #5 the fact he stated he wanted to use 4 conductor focused me on that being the cable between his pilot switches.

At anyrate I guess he isn't going to use it.

Theatertech85

You are correct if the op has nm 4 conductor he cannot bury it. 4 conductor nm has been around for a long time but is usually only found at supply houses and not the big box stores. 2/2 with ground (shown in the images I posted) is relatively new I believe and was brought out to provide two circuits and two neutrals to bedrooms due to afci requirements. It used to be we ran a multiwire when we needed two circuits but with the afci requirement we can't share a neutral. 

Say I wanted to ask you something about stage lighting. When you set up outdoors say to light a stage for a band, is gfci required for your receptacles? Seems they would be tripping all the time and I don't see anything in the NEC articles that require gfci for stage lighting. 

Also how do you guys do your distribution wiring? Do you have feeders to distribution panels with duplex plugs or twist locks? And circuit breakers mounted on those panels or how do you do the ocpd for your lighting cable runs?


----------



## theatretch85

As for the ground not being shown, I knew that it wasn't but the reason I stated that is you showed 4 total wires in your diagram between the two switches, and there was still no ground. Meaning that wire would have to be a 5 wire cable not 4, so in that diagram it would not be possible to do that with 4 wires (with one being a ground) like is in standard 3 wire plus ground.

Stage lighting does not require GFCI outlets or breakers. If its a big lighting setup, we use the 36 channel dimmer rack, which takes 4 cams in the back (ground, neutral, line 1, line 2) on 2/0 stranded wire (yes 100' x 4 conductors of this is VERY heavy). All the lighting OCPD is done at the Dimmers, as the power switches for each output is a circuit breaker; 3 rack mounted dimmers, with 12 channels each. 

Stage power and amp racks it gets a little iffy. The generator the company owns, has 3 50 amp spider boxes which has single 20 amp outlets (not duplex) with GFI's mounted in the box right next to them, and all on their own 20 amp breakers. I believe 6 20 amp circuits, and one 240 volt 30 amp circuit (only a 3 wire, so no 120/240). The breakout boxes are daisy-chain able, but share the same double pole 50 amp breaker on the generator. We have had some nuisance tripping on some of the GFI's on occasion, and I think we narrowed it down to being a faulty GFI (was only used for sound power). We rarely use the 100 amp sub panel for anything on the generator, since it requires it to be tapped, and its pointless with the 50 amp spider boxes (that and the cable is made up of 6 and 8 gauge wire, not exactly sized properly). When power is provided at the location, we usually use the 100 amp panel and tap right in, that 100 amp panel does not have any GFCI's in it at all (I know, I didn't wire it). 

If you want to know more, send me a PM and I will tell you more, I already feel like I kinda hi-jacked this thread....


----------



## chris75

theatretch85 said:


> Stubbie, your drawing would require a 5 wire cable to complete. It would require a Ground, Neutral, plus 3 hot wires (two travelers, plus a common); and you cant use the ground as the neutral wire. I am guessing this 4 wire cable the op has is 3 wire + ground (bare ground, white, black, red). Unless the op is running conduit the entire distance from switch box to switch box, and pulling individual wires through the only logical way to do this would be what HouseHelper and I have suggested is to power the garage light from the house side of the circuit.



The grounds are never drawn for picture clarification. And no one ever includes the ground as a conductor count. Examples. 14-2, 14-3, etc, etc,....


----------



## theatretch85

Yes chris75 I know that, but referencing the fact that the op has a 4 wire UF cable, its not going to be this fancy 5 wire cable. The drawing stubbie had was already at 4 wires and still didn't include a ground, meaning it would have to be a 14/4 w/g making it 5 wires total. I am not new to electrical wiring, I have been doing electrical work since I was about 7 years old. I have done plenty of work with electrical wiring and have worked on some complex setups. I was just trying to indicate that the diagram would need to be done with a 5 wire cable, when the op clearly stated he only has a 4 wire cable (which is 1 less than 5).

So now are we done with drilling in the fact that most electrical drawings don't show the ground for simplicity?


----------



## Stubbie

> So now are we done with drilling in the fact that most electrical drawings don't show the ground for simplicity?



I certainly hope so......:thumbsup:

My interest in stage lighting is directed at my good friends son ( 21 years young) who wants very much to have a career or business in theater/stage lighting. He has over the last couple years spent his last dime on stage lighting trusses and jacks and lights of all sorts and a nice new tandem trailer to haul all the stuff in.... Of course dimmer racks and programing software. He has his first job in a few weeks at a bar-b-que contest lighting an outdoor stage for a live band. First he is going to put on a fireworks show (he is also a class one pyro-technician) and set up his equipment for a family gathering the week before his job. 

So I was going to refer him here to open a thread and was wondering if you would assist him with his questions.....and mine of course...

I hope you will hang out here on the forum over time as you offer a area of expertise that I at least am not overly familiar. Any forum is better with professionals from different areas of skill.

I don't think you hijacked the thread....I think I steered it to the left when it should have went to the right.....:wink:

Stubbie


----------



## SaxTeacher

Stubbie: Thank you, your wiring diagram was *exactly* what I was going to do. 

theatretch85: Yes, it's 14-4 NM cable (Romex) and I got a 250 foot roll of it at a local electrical supply house. It costs more but it's great for not having two separate lengths of 14-2.

Househelper: Thank you, your suggestion is an excellent one. I will simply take the feed from the house side and thereby save myself one 75-foot length of wire.

By the way, for those that were wondering whether I was using UF (direct bury) cable: I did that in the past (10-3 UF) when I brought power out from the house to the garage; but this time I am burying gray PVC conduit. This means I won't be using any NM or UF cable; it will be THHN wire inside the conduit.

Thanks again to all for the advice.


----------



## Stubbie

So I guess you get to admire your 4 conductor nm for a while.....:thumbsup: I'm glad things worked out. I had a bit of trouble understanding your intentions when you said you wanted to use 4 conductor cable but almost always those of us here on the forum eventually get it figured out. To your credit using 4 conductor nm-b was exactly what you wanted had you had the right configuration and a little different installation requirement.


----------



## 747

Stubbie my Father is a Ford mtr company retiree UAW Local 588 and my brother in law currently works at the chicago heights stamping plant local 588. My Father was a QC inspector. Brother in law is currently Material handler. Not sure what my brother in law seniority is i'm thinking 76 or 77 or 78 seniority. My father before retirement had 56 seniority. Brother in law had a sweet job and they eliminated it. So now he is material handler. He hooks up the the racks at the end of the line and pulls them where they need to go.


----------



## Stubbie

Yes I have met a few people from 588 at meetings in Detroit years back...I'm retired now. Sorry but i just can't pull the names out of my head right now. My seniority was 1974, Local 249 Claycomo, Missouri Assembly and then transferred to Kansas City Parts Distribution.


----------



## theatretch85

SaxTeacher said:


> By the way, for those that were wondering whether I was using UF (direct bury) cable: I did that in the past (10-3 UF) when I brought power out from the house to the garage; but this time I am burying gray PVC conduit. This means I won't be using any NM or UF cable; it will be THHN wire inside the conduit.


Just to make sure you meant "THWN" not "THHN" in that conduit. Since its still considered a "wet" location it needs to have the "W" in the label which makes it rated for a wet location.


Stubbie, yes I would be more than happy to provide any assistance I can in the way of stage lighting and power distribution. Either put up a new thread or send me a message either way. I haven't been on here all too often, but i'll make it a point to check back more often.


----------



## 747

Stubbie said:


> Yes I have met a few people from 588 at meetings in Detroit years back...I'm retired now. Sorry but i just can't pull the names out of my head right now. My seniority was 1974, Local 249 Claycomo, Missouri Assembly and then transferred to Kansas City Parts Distribution.


Claycomo, missouri assembly is that where they use to make the mercury mystique at Meaning is that kansas city missouri assembly plant? I use to have a mercury mystique bought it new got the a plan because of my father being a retiree and it was made at kansas city assembly this is why i asked.:thumbsup:


----------



## Stubbie

747 said:


> Claycomo, missouri assembly is that where they use to make the mercury mystique at Meaning is that kansas city missouri assembly plant? I use to have a mercury mystique bought it new got the a plan because of my father being a retiree and it was made at kansas city assembly this is why i asked.:thumbsup:


Yes you have it right.


----------



## SaxTeacher

*I got it wrong*

Well, I ran all the wires - took power from the house to the three-way-switch with pilot light, then used 14-3 (two travelers and a neutral) from there to the 3-way switch in the garage. Hooked it all up and the three way switches work - but the pilot does not. The pilot says on all the time, regardless of whether the fixture is on or not!

Turns out that the wiring diagram (attached) from Pass & Seymour Legrand is just simply DEAD WRONG. A wiring diagram that I received by email from Leviton (attached) confirms it.

If the pilot light is in the 3-way switch at the LOAD end, then only 3-wire (two travelers and a neutral) is required between the two switches. BUT - if the pilot light is in the 3-way switch at the LINE end (as it is in my case), then 4-wire (two travelers, a neutral, and an additional wire to connect the pilot light to the load) is needed!

Needless to say I am most disappointed that, despite reading the Pass & LeGrand diagram, and asking for help here, I still didn't get it right. Now I have to pull out a bunch of 14-3 and replace it with 14-4... a real waste of money and time.

Hopefully someone else can learn from my experience!


----------



## stmijaar

*Current Transformers*

Does anyone out there understand all the different spec parameters given by different mfrs of these thing?
My 1st post....I'm a novice!


----------



## theatretch85

stmijaar said:


> Does anyone out there understand all the different spec parameters given by different mfrs of these thing?
> My 1st post....I'm a novice!


Wow, you do realize its been 5 months since anything was said in this thread and your topic has NOTHING to do with it! Seriously, start a new thread, also start by reading the

Views: *14,594*  *Announcement*: PLEASE READ: Posting Rules and Disclaimer

Found at the top of the forum listing.


----------



## stmijaar

is that good, bad or indifferent? 
Actually I'm experimenting with a 3-way switch with a pilot llight on the line (NOT LOAD) side and current transformers come into play.
NO additional wire runs needed in the house for this!.


----------



## charlesW

*Wiring Two 3way Pilot Light Switches - Each with pilot light.*



Stubbie said:


> This is what I understand you have and using your 4 conductor cable


I ordered two 3way switches (Leviton 5246-I - 15A Duplex Style 3-Way Switch w/ Pilot Light), each-one with a pilot light so to know when the oil burner is turned on from two locations. Trying to conserve fuel oil burning a direct hot water heater. After searching the web, seems there is no example out there- i hope i can run 2 pilot lights on the same system... appreciate your time, Thanks, Charles


----------

