DIY Home Improvement, Remodeling & Repair Forum > DIY Home Improvement > Electrical and Wiring > single-pole double-throw switch




Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old 12-27-2010, 08:29 AM  
kentannenbaum
Junior Member
 
Join Date: Oct 2010
Location: Catskill, New York
Posts: 13
Default single-pole double-throw switch

I just ran a 12-3 line for 240v baseboard heaters and now want to use one of those lines for an A/C in the same room during the summer. The switch is really expensive, but is there anything wrong with using an in-line SPDT 20amp switch that CLEARLY would cut half the power to the heaters during the summer only? The switch has center "off" position and two "on" positions to channel current one way or the other. Thanks.



__________________

Last edited by kentannenbaum; 12-27-2010 at 12:08 PM.
kentannenbaum is offline  
 
Reply With Quote Quick reply to this message
Old 12-27-2010, 01:44 PM  
kok328
Supporting Member
HRT_SUPPORTER.png
 
Join Date: Nov 2007
Location: Grand Blanc, MI
Posts: 2,181
Liked 104 Times on 91 Posts
Likes Given: 61

Default

Is the A/C 120V or 240V?

If 120V, where you getting your neutral & ground from?

To the best of my knowledge a SPDT will cut both legs of power in a 2-pole circuit.



__________________
kok328 is offline  
 
Reply With Quote Quick reply to this message
Old 12-27-2010, 02:49 PM  
kentannenbaum
Junior Member
 
Join Date: Oct 2010
Location: Catskill, New York
Posts: 13
Default

This is a 12/3 cable. My plan for the 120v A/C WAS to use the white wire as neutral and of course the copper as ground AND to use the SPDT to split one of the hot wires which goes to the baseboards in winter and use that "split off" leg for the 120v A/C in summer.
BUT, I decided to run a dedicated 12/2 cable to the A/C which doesn't exist yet. Too bad I didn't think to go to an electric supply house a use 12/4. Would have saved a lot of time. Again thanks.

__________________
kentannenbaum is offline  
 
Reply With Quote Quick reply to this message
Old 12-28-2010, 08:54 AM  
JoeD
Contractor
 
Join Date: Mar 2006
Location: Welland, Ontario
Posts: 948
Liked 100 Times on 82 Posts
Likes Given: 2

Default

Quote:
Originally Posted by kok328 View Post
To the best of my knowledge a SPDT will cut both legs of power in a 2-pole circuit.
SPDT = Single pole double throw. Single pole means it only cuts on leg.
If you want to cut both legs you need a DPDT.Double pole double throw.

Not sure how the code feels on this but a normal three way switch could work. Put one hot on the common and the heater on one traveller and the AC on the other traveller. Only one device will be able to be on at any time.
__________________
JoeD is offline  
 
Reply With Quote Quick reply to this message
Old 12-29-2010, 09:17 AM  
speedy petey
Lic.Electrical Contractor
 
Join Date: Mar 2006
Posts: 445
Liked 39 Times on 27 Posts
Likes Given: 17

Default

What happened, you got tired of this? SPDT double-throw switch

LOL

__________________
speedy petey is offline  
 
Reply With Quote Quick reply to this message
Old 01-27-2011, 09:07 PM  
ajaynejr
Junior Member
 
Join Date: Jan 2011
Location: Nashua, NH
Posts: 6
Default

An ordinary 3 way switch is a single pole double throw switch.

Be sure that the switch current rating is sufficient before using it to control a heater.

__________________
ajaynejr is offline  
 
Reply With Quote Quick reply to this message
Old 01-28-2011, 04:59 AM  
kentannenbaum
Junior Member
 
Join Date: Oct 2010
Location: Catskill, New York
Posts: 13
Default

Actually, I decided to run another separate line for the A/C. Thanks very much for the insight.



__________________
kentannenbaum is offline  
 
Reply With Quote Quick reply to this message
Reply


Quick Reply
Message:
Options

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter DIY Home Repair Forum Replies Last Post
Single switch to receptacle jeff7 Electrical and Wiring 11 09-18-2012 08:44 AM
single vs double pole for 240v kentannenbaum Electrical and Wiring 2 12-21-2010 04:52 AM
single pole switch 1oldhouse Electrical and Wiring 3 06-29-2010 10:04 AM
Single Pole Switch s2horn Electrical and Wiring 7 08-25-2009 02:31 PM
how many lights on a single light switch? Philphine Electrical and Wiring 8 04-17-2007 10:54 AM