Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Electrical

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Search this Thread Display Modes
Old 10-20-2009, 06:39 PM   #1
Member
 
Join Date: Aug 2009
Posts: 33
Share |
Default

T stat with 2 wires on 240?


I recently installed a 240V hydronic electric baseboard heater in a bathroom.
The thermostat that I purchased to control the heater was sold with the heater as a kit from a company in SC. The T stat has a triac in it to vary the current (or is it voltage?) supply to the heater, based on rise needed, room temp......
This T stat is single pole. I'm now hearing that single pole on 240 is against code in the US. Does the triac change that or should this product not be sold here?

Wiring is as follows:

1 side of supply to T stat
2nd side of supply to heater element
2nd side of heater element ( temp limit switch) to other side of T stat

Am I safe?
Heater has a chassis ground that is connected to supply ground

Thanks.

OffRoadAudio is offline   Reply With Quote
Old 10-20-2009, 07:19 PM   #2
Member
 
Join Date: Oct 2007
Posts: 2,294
Default

T stat with 2 wires on 240?


A switch must turn both legs off but your thermostat is considered control wiring and may switch just one leg.

220/221 is offline   Reply With Quote
Old 10-20-2009, 07:30 PM   #3
Member
 
Join Date: Aug 2009
Posts: 33
Default

T stat with 2 wires on 240?


Great - thanks for the clarification.
OffRoadAudio is offline   Reply With Quote
Old 10-20-2009, 09:33 PM   #4
Electrical Contractor
 
kbsparky's Avatar
 
Join Date: Sep 2008
Location: Delmarva
Posts: 3,360
Default

T stat with 2 wires on 240?


Single pole line voltage thermostats do not provide "disconnecting means" for connected heating units. Because of this, they do not have an "off" position.
__________________
-KB

Life is uncertain -- eat dessert first!!
kbsparky is offline   Reply With Quote
Old 10-20-2009, 10:04 PM   #5
Member
 
Join Date: Nov 2007
Location: Nashua, NH, USA
Posts: 6,839
Default

T stat with 2 wires on 240?


While they make two pole full line voltage/current controlling thermostats for electric heaters, it is actually rare that both poles open or close automatically at exactly the same time. I have even used some whose calibration is off far enough that turning the dial manually also has the poles opening and closing at noticeably different dial positions.

In normal operation with both leads to one heater connected, this usually means that one of the contacts does all of the switching under load. If instead the double pole thermostat is used to control one lead respectively of two heaters, usually the temperature will fall further enough that the second heater will be switched off (and on again) before the first is switched back on.
__________________
Stop wasting time re-adjusting the pattern. Have several lawn sprinklers, one for each pattern.

Last edited by AllanJ; 10-21-2009 at 06:49 AM.
AllanJ is offline   Reply With Quote
Old 10-21-2009, 06:15 AM   #6
Electrical Contractor
 
kbsparky's Avatar
 
Join Date: Sep 2008
Location: Delmarva
Posts: 3,360
Default

T stat with 2 wires on 240?


That is correct. The only way to ensure both poles are open with a double pole thermostat is to turn it "off"
__________________
-KB

Life is uncertain -- eat dessert first!!
kbsparky is offline   Reply With Quote
Old 12-13-2011, 06:52 PM   #7
Newbie
 
Join Date: Dec 2011
Posts: 1
Default

T stat with 2 wires on 240?


so it's ok to use single pole t stat on 240V?

Kris. is offline   Reply With Quote
Reply


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 Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Switch Junction box has 3 sets of 3 wires. Can't get dimmer to work knockout Electrical 12 06-10-2014 12:52 AM
Unfused connectors MELTED House wires WHAT TO DO??? jamiedolan Electrical 63 02-12-2009 06:01 PM
LUX digital stat Trane XE80 intermittant problem rossl56 HVAC 6 12-26-2008 05:53 AM
replacing outlet with 3 white/3 black wires gpet573 Electrical 4 06-03-2008 02:55 PM
Two black wires with one white! Please help! ibs325 Electrical 15 11-18-2007 09:38 PM




Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.