240v electric heater install in garage
#1
11-27-15, 02:53 PM
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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 02:59 PM. Reason: Pictures
#2
11-27-15, 02:59 PM
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.
#4
11-27-15, 03:21 PM
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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.
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
11-27-15, 03:24 PM
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.
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
11-27-15, 03:30 PM
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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
#8
11-27-15, 03:49 PM
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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.
#10
11-27-15, 04:26 PM
#13
11-27-15, 06:01 PM
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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
11-28-15, 06:50 AM
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.
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.
