Go Back  DoItYourself.com Community Forums > Electrical, AC & DC. Electronic Equipment and Computers > Electrical - AC & DC
Reload this Page >

3 way (SPDT) Switch to alternate light sources?

3 way (SPDT) Switch to alternate light sources?


   
  #1  
Old 02-26-19, 02:12 PM
B
Member
Thread Starter
Join Date: Nov 2016
Location: USA
Posts: 104
Received 0 Likes on 0 Posts
3 way (SPDT) Switch to alternate light sources?
Hey guys, quick question...

Instead of using multiple 3-way switches for one run of lights, can you use one 3-way switch to alternate between 2 light sources?

I assumed so but I figured I'd double check...

I want to wire a switch in the garage so it turns a ceiling light on/off, but when it's "OFF" I want power to go to a small motion detector light. I could just run the ceiling light from one "traveler" lug and the motion light from the other "traveler" lug, correct? As long as the neutrals are all connected in the switch box?

Thanks
Brian
 
Like
  #2  
Old 02-26-19, 02:27 PM
J
Member
Join Date: Sep 2002
Location: welland ontario
Posts: 8,369
Received 472 Likes on 390 Posts
It will work as you have described it.
 
Like
  #3  
Old 02-26-19, 05:12 PM
L
Member
Join Date: Nov 2015
Posts: 1,814
Received 177 Likes on 152 Posts
Yes that will work. It is called common instead of traveler.
 
Like
  #4  
Old 02-27-19, 12:15 PM
B
Member
Thread Starter
Join Date: Nov 2016
Location: USA
Posts: 104
Received 0 Likes on 0 Posts
Is there any way to do this involving 2 switches? As in, two switches to control one light, but when that light is off, another would be powered? Getting complicated here... lol

Thanks
Brian
 
Like
  #5  
Old 02-27-19, 01:40 PM
A
Member
Join Date: Mar 2010
Location: USA
Posts: 4,999
Likes: 0
Received 244 Likes on 224 Posts
Is there any way to do this involving 2 switches? As in, two switches to control one light, but when that light is off, another would be powered? Getting complicated here.
Actually this one is not too difficult. Use a pair of double pole double throw switches, which are each like two 3 way switches in one device with a shared toggle.

You will need extra large boxes, namely 28 cubic inches for 14 gauge wiring with power coming into one box and the light wiring going out of the other box.

Note: In a typical 3 way switch the dark terminal is the common terminal and the lighter colored terminals are for the travelers. For each of the two DPDT switches you need to first identify the two sides each with one dark terminal and two lighter terminals..
 
Last edited by AllanJ; 02-27-19 at 01:58 PM.
Like
  #6  
Old 02-27-19, 03:25 PM
B
Member
Thread Starter
Join Date: Nov 2016
Location: USA
Posts: 104
Received 0 Likes on 0 Posts
Are DPDT switches the same as a standard 4-way from the box store?

I've worked with DPDT switches in guitars but never in a wall switch. Not sure what to look for.

Thanks!
Brian
 
Like
  #7  
Old 02-27-19, 04:30 PM
ray2047's Avatar
Member
Join Date: Mar 2006
Location: USA
Posts: 33,575
Likes: 0
Received 15 Likes on 13 Posts
Are DPDT switches the same as a standard 4-way from the box store?
No. The switches contain internal jumpers and there is no off position.

Not sure what to look for.
You need DPDT center off. Look for a rating of at least 15a at 200v.
 
Last edited by ray2047; 02-27-19 at 06:26 PM.
Like
  #8  
Old 02-27-19, 05:48 PM
L
Member
Join Date: Nov 2015
Posts: 1,814
Received 177 Likes on 152 Posts
Not just DPDT. That won't work. You need DPDT center off.
I don't think center off is necessary, although that might be easier to find.

You can achieve what the op wants by using one side of DPDT switches for ceiling fan light and the other side for motion sensor light. Treating each as 3 way switch.
Center off is necessary only if both ceiling fan and motion sensor light needs to be off.
 
Like
  #9  
Old 02-27-19, 06:27 PM
ray2047's Avatar
Member
Join Date: Mar 2006
Location: USA
Posts: 33,575
Likes: 0
Received 15 Likes on 13 Posts
I have edited my post to eliminate "center off".
 
Like
  #10  
Old 02-27-19, 07:57 PM
A
Member
Join Date: Jun 2012
Location: USA
Posts: 1,798
Received 83 Likes on 75 Posts
If no "off" position is needed why wouldn't a 3-way connected to a 4-way work? Power to the common of the 3-way. Two travelers from there to feed the 4-way. Then then other two terminals of the 4-way could go to the light and motion detector light.
 
Like
  #11  
Old 02-28-19, 03:49 AM
L
Member
Join Date: Nov 2015
Posts: 1,814
Received 177 Likes on 152 Posts
Power to the common of the 3-way. Two travelers from there to feed the 4-way. Then then other two terminals of the 4-way could go to the light and motion detector light.
That would actually work.
 
Like
  #12  
Old 02-28-19, 10:07 AM
A
Member
Join Date: Mar 2010
Location: USA
Posts: 4,999
Likes: 0
Received 244 Likes on 224 Posts
deleted ...................
 
Like
  #13  
Old 02-28-19, 10:21 AM
M
Member
Join Date: Mar 2009
Location: Northern Virginia
Posts: 4,240
Received 22 Likes on 17 Posts
You could also use a photocell to control power to the motion detector light. Then you'd just need a single pole to control the garage light.
 
Like
  #14  
Old 02-28-19, 10:59 AM
Z
Forum Topic Moderator
Join Date: Sep 2005
Location: USA
Posts: 6,402
Received 354 Likes on 316 Posts
Be aware that many motion detectors go into different test modes when being turned off then back on again in under a minute. The ones I've seen will either switch to always on, or a test mode where the motion sensor is on regardless of time of day and turns on the light for only 5 sec at a time.
To reset it back to its normal motion detection, you need to turn it off for over 1 minute, then back on.

I can see that potentially being an issue if you turn on the light to get something, then turn it off. You may be able to get around this by switching the light after the motion detector. Or possibly find a motion detector that doesn't do this.
 
Like
  #15  
Old 02-28-19, 02:32 PM
L
Member
Join Date: Nov 2015
Posts: 1,814
Received 177 Likes on 152 Posts
You could also use a photocell to control power to the motion detector light.
I thought about that as well, but if a lamp bright enough to light up the room is installed on the motion sensor light, photocell will detect that and turn itself off.
 
Like
 

Thread Tools
Search this Thread
Search this Thread:

Advanced Search
Do Not Sell or Share My Personal Information
Cookie Settings

DoItYourself.com®, founded in 1995, is the leading independent home improvement and repair website. We welcome your comments and suggestions. All information is provided "AS IS." Website operating problems contact webmaster@doityourself.com. Questions of a Do It Yourself nature should be submitted to our "DoItYourself.com Community Forums". Copyright© 1995-2023 MH Sub I, LLC dba Internet Brands. All rights reserved. You may freely link to this site, and use it for non-commercial use subject to our terms of use. View our Privacy Policy here.

 
Ask a Question
Question Title:
Description:
Your question will be posted in: