# Using 3-way switch as 2 single pole switch legs



## nick.pei (Jun 15, 2009)

I was just thinking about lighting for a building I am planning to build. There is only going to be one entrance and I am planning on having a lamp on all the time when unoccupied for security. 

Have any of you ever used a 3 way switch to control the single lamp and all the main building lighting. When flipped in down (traditional off position) the single light will be fed and then when flipped on, the single light goes off and powering the T8's?


----------



## McClary’s Electrical (Feb 21, 2009)

nick.pei said:


> I was just thinking about lighting for a building I am planning to build. There is only going to be one entrance and I am planning on having a lamp on all the time when unoccupied for security.
> 
> Have any of you ever used a 3 way switch to control the single lamp and all the main building lighting. When flipped in down (traditional off position) the single light will be fed and then when flipped on, the single light goes off and powering the T8's?


 
I've done similar, and it seems to fit your application, so I would do it


----------



## NolaTigaBait (Oct 19, 2008)

Pretty good idea. I never would have thoght of it.


----------



## nick.pei (Jun 15, 2009)

NolaTigaBait said:


> Pretty good idea. I never would have thoght of it.


Same here, It was just a light going off inside my head before i fell alseep.
Do it this way instead of using a timer or photocell to control it because I do not want it on when I am in the building.


----------



## 480sparky (Sep 20, 2007)

I do something similar with motion sensor lights. 3-way in one position sends power to the electronics, the other sends power right to the lamps.


----------



## oldtimer (Jun 10, 2010)

480sparky said:


> I do something similar with motion sensor lights. 3-way in one position sends power to the electronics, the other sends power right to the lamps.


 


I have used a three way switch this way also, and I can't see anything wrong with using it this way. It's not what it was designed for, but it works,and it is safe, I M O .


----------



## mattsilkwood (Sep 21, 2008)

I used one for a receptacle for open and closed signs. It worked pretty slick.


----------



## Voltech (Nov 30, 2009)

I have rigged job fans with 3ways to replace bad speed control switches


----------



## Bkessler (Feb 14, 2007)

This is a great thread. I can think of lots of scenarios this would come in handy.


----------



## nolabama (Oct 3, 2007)

I have seen three way switches wired in this manner also.


----------



## user438 (Jun 6, 2007)

I use a 3 way to install a photocell bypass switch so that the building lights can be turned for maint. during the day without having to tape the photocell up


----------



## frenchelectrican (Mar 15, 2007)

There were couple spots that I did use the three way switch for heat and cool postion on one unit I have done. { it was replace with proper item at later date }

The other spot I use kinda getting common item is switching the motion sensor on automatique mode or manual mode { the manual mode will go directly to the luminaire.}

Merci.
Marc


----------



## JoeKP (Nov 16, 2009)

Is there any way that this could be setup to violate a part in the NEC? I have always thought this was in someway not allowed. If it is allowed, I cant wait to finally not be annoyed that I couldnt use it


----------



## 480sparky (Sep 20, 2007)

JoeKP said:


> Is there any way that this could be setup to violate a part in the NEC? I have always thought this was in someway not allowed. If it is allowed, I cant wait to finally not be annoyed that I couldnt use it


What? A wiring method, or a use of a 3-way?


----------



## JoeKP (Nov 16, 2009)

using a 3way as stated above


----------



## 480sparky (Sep 20, 2007)

JoeKP said:


> using a 3way as stated above



Using it which way state above?


----------



## Forrester (Sep 5, 2010)

480sparky said:


> I do something similar with motion sensor lights. 3-way in one position sends power to the electronics, the other sends power right to the lamps.


Does back feeding the electronics cause any issue?

FWIW, most motion detector lights will stay on all the time if you flip the switch quickly. To get them back into motion detector mode you just flip the switch off for 10 seconds or so.


----------



## JoeKP (Nov 16, 2009)

480sparky said:


> Using it which way state above?


Any of the ways stated above


----------



## 480sparky (Sep 20, 2007)

Forrester said:


> Does back feeding the electronics cause any issue?..........


Never have had any.



Forrester said:


> ........FWIW, most motion detector lights will stay on all the time if you flip the switch quickly. To get them back into motion detector mode you just flip the switch off for 10 seconds or so.


Yeah, but try explaining that to the average customer. They may understand it, but only until you get to the end of the driveway.


----------



## davey (Aug 14, 2010)

The practice is explicitly permitted, I believe, by Exception 1 to 404.7 (2008): "Vertically operated double-throw switches shall be permitted to be in the closed (on) position with the handle in either the up or the down position."

A three-way is one form of single-pole, double-throw switch.


----------

