240v electric heater install in garage

Reply

  #1  
Old 11-27-15, 03:53 PM
G
Member
Thread Starter
Join Date: Nov 2015
Posts: 6
Received 0 Votes on 0 Posts
240v electric heater install in garage

Hey guys, was needing some help installing my new heater in my garage. First off the previous owner had a large welder installed in the garage so I already had a 240v outlet for it. My question is, how do I convert this outlet over to power my new heater? I'm thinking my breaker set up won't support this not sure.
 

Last edited by Gofftylerl; 11-27-15 at 03:59 PM. Reason: Pictures
  #2  
Old 11-27-15, 03:59 PM
P
Temporarily Suspended
Join Date: Jul 2008
Location: NY
Posts: 10,982
Received 0 Votes on 0 Posts
What is the make & model, of the heater? Is there a built in thermostat or does a thermostat have to be mounted, separately? You may not be able to use the outlet.
 
  #3  
Old 11-27-15, 04:01 PM
G
Member
Thread Starter
Join Date: Nov 2015
Posts: 6
Received 0 Votes on 0 Posts
It's a comfort zone model cz220, with a built in thermostat
 
  #4  
Old 11-27-15, 04:21 PM
C
Member
Join Date: May 2015
Location: USA
Posts: 3,138
Received 2 Votes on 2 Posts
It's designed to be hard wired, not plugged into an outlet. Do you plan to hang this high on wall or on the ceiling? Assuming you do, you'll want to run conduit from your existing 240 outlet box (remove the outlet) to a box near the heater, and then run BX or greenfield from that box to the heater. You'll need 10 ga wire and the breaker will need to be 25 or 30 amps, dual pole. This assumes the wiring to your existing box is at least 10 gauge; if not, you'll have to make a new run to the panel.

If it were me, in between the existing outlet and the box for the heater, I'd put a 30 amp disconnect switch so I could totally kill the power to the heater when not in use.
 
  #5  
Old 11-27-15, 04:24 PM
P
Temporarily Suspended
Join Date: Jul 2008
Location: NY
Posts: 10,982
Received 0 Votes on 0 Posts
Are you saying that the plug on the heater doesn't match the outlet that you have? A quick search told me that the heater requires 20 amps. What breaker is currently installed?

Edit: The pic that I saw showed a plug, on the power cord. However, Carbide could be correct & it needs to be hardwired. I would still look at the amperage.
 
  #6  
Old 11-27-15, 04:30 PM
G
Member
Thread Starter
Join Date: Nov 2015
Posts: 6
Received 0 Votes on 0 Posts
Yes I planned on hard wiring it up but I don't think the previous setup will work.I have a breaker box in the garage with a dual 40 amp setup running to the what was the old outlet, I removed the outlet and now just have the wires from the box. Not sure on the codes for wires but this is a red, black, white and copper wire with a black jacket.Says type NM-B 8-3 with ground 600 volts
 
  #7  
Old 11-27-15, 04:34 PM
G
Member
Thread Starter
Join Date: Nov 2015
Posts: 6
Received 0 Votes on 0 Posts
I would just post pics but haven't figured that out yet lol, kinda new here
 
  #8  
Old 11-27-15, 04:49 PM
Tolyn Ironhand's Avatar
Group Moderator
Join Date: Nov 2007
Location: United States
Posts: 13,802
Received 252 Votes on 220 Posts
If you hard wire it you will still need a disconnect, this can be a simple A/C disconnect pullout. According to the model number you posted it draws 20.9 amps on max setting. You could either change the breaker to a 25 or 30 amp two pole, or install an A/C fusible disconnect and install 25 or 30 amp fuses. You should use some type of flexible conduit to protect the wires going to the unit.
 
  #9  
Old 11-27-15, 05:20 PM
F
Member
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 18,495
Received 36 Votes on 28 Posts
Tolyn, he has to go to a 30 ampere circuit since the NEC requires a circuit for space heating to be sized at 125% of the load. 125% of 20.9 amperes is 26.13 amperes.
 
  #10  
Old 11-27-15, 05:26 PM
ray2047's Avatar
Member
Join Date: Mar 2006
Location: USA
Posts: 33,583
Received 13 Votes on 11 Posts
  #11  
Old 11-27-15, 06:11 PM
G
Member
Thread Starter
Join Date: Nov 2015
Posts: 6
Received 0 Votes on 0 Posts
Would a 40 amp 2 pole be to much?
 
  #12  
Old 11-27-15, 06:14 PM
G
Member
Thread Starter
Join Date: Nov 2015
Posts: 6
Received 0 Votes on 0 Posts
Thanks ray2047 I'm using a iPhone tho
 
  #13  
Old 11-27-15, 07:01 PM
F
Member
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 18,495
Received 36 Votes on 28 Posts
If you used the 40 ampere circuit breaker you would need to use #8 wiring and the heater would not have the proper overload protection. 30 ampere circuit breaker is the correct size and #10 conductors.
 
  #14  
Old 11-28-15, 07:50 AM
A
Member
Join Date: Mar 2010
Location: USA
Posts: 4,291
Received 109 Votes on 101 Posts
The heater instructions or name plate may give a maximum amperes circuit rating and the breaker for that branch circuit may not exceed that. In addition the wire size for the branch circuit must be appropriate for the circuit breaker rating as stated prreviously.

Generally, if a hard wired appliance or heater or tool would use more than half the branch circuit amperage rating, it should be the only load on that circuit. Then you would downsize the breaker as needed.

For heaters and other equipment with power plugs, the plug and the matching circuit receptacle imply the required amperes rating for the branch circuit. Such a receptacle may not go on a higher amperage circuit and the equipment almost certainly draws more current than the next smaller plug will allow.
 
  #15  
Old 11-28-15, 08:39 AM
CasualJoe's Avatar
Member
Join Date: Jan 2010
Location: United States
Posts: 10,758
Received 97 Votes on 87 Posts
Would a 40 amp 2 pole be to much?
Yes, you should use a 30 amp 2 pole breaker.
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: