Thermostat Wiring Question

Reply

  #1  
Old 04-21-05, 05:00 PM
Member
Thread Starter
Join Date: Nov 2004
Location: north dakota
Posts: 159
Thermostat Wiring Question

Installing a 220V baseboard heater. I have this double pole (4wire) line voltage thermostat with 2 black & 2 red wires. I see the wires are stranded. Do I twist the stranded together with the solid wire? Never worked with stranded before.

Also, this is a wall mount thermostat. Necessary to cut a hole in my bedroom wall. I'll have 2 red connections, 2 black connections and 1 ground connection. How large (cu. in.) box is required? I bought a box for 'old work' but I see it's 14in. Sufficient?
 
Sponsored Links
  #2  
Old 04-22-05, 01:07 AM
Member
Join Date: Sep 2003
Location: Central New York State
Posts: 13,973
What size wire is required?
 
  #3  
Old 04-22-05, 03:22 AM
Member
Thread Starter
Join Date: Nov 2004
Location: north dakota
Posts: 159
Heater is 220V 1500W supplied with 12-2 with Ground
 
  #4  
Old 04-22-05, 03:39 AM
Member
Join Date: Sep 2003
Location: Central New York State
Posts: 13,973
Yes, 14 inches is sufficient. You have five conductors, 2 black, 2 red and the grounds (all grounds count as 1).
 
  #5  
Old 04-22-05, 10:58 AM
Member
Join Date: Dec 2002
Location: Connecticut USA
Posts: 144
No, 14 cubic inches is not sufficient.

Using external cable clamp(s) in a steel box or a plastic box with built-in clamps, the box will need to be at least 15.75 in.³.

Using a steel box with an internal clamp(s) the box will need to be at least 18 in.³.
 
  #6  
Old 04-23-05, 06:50 AM
Member
Thread Starter
Join Date: Nov 2004
Location: north dakota
Posts: 159
Got a 18in³ plastic box. First supplier only had the one option as far as 'old work'. Looked fine until I got it home and saw '14' in the bottom.
Bigger box says up to 8 - #12 wires. Smaller one doesn't say. I assumed 14in³ would be OK, but since I now have this 18in³ I'll use it.

So do I just twist stranded & solid wires together with wirenuts?
Tanks.
 
  #7  
Old 04-23-05, 11:33 PM
Member
Join Date: Sep 2003
Location: Central New York State
Posts: 13,973
Hi bolted, could you tell me how you come up with 15.75. I cannot come up with that number no matter how I play the game.
 
  #8  
Old 04-24-05, 02:10 AM
Member
Join Date: Dec 2002
Location: Connecticut USA
Posts: 144
Skramy,

When mixing a solid and stranded together, I find it easier not to pretwist. If you try and pretwist, the stranded will often just wrap itself around the solid which can prevent the wirenut from actually biting into the solid conductor. Either way is OK, just a personal preference.

Morning Bob,

12/2 in counts as 3 conductors
12/2 out counts as 2 conductors
T-stat counts as 2 conductors
 
  #9  
Old 04-24-05, 03:09 PM
Member
Join Date: Sep 2003
Location: Central New York State
Posts: 13,973
Bolted,

I agree with the 12/2 and 12/3 wire count. I didn't count the thermostat wires...
 
Reply

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


Thread Tools
Search this Thread
Display Modes
'