HVAC guys here? Garage?

[Fuddy1952]

I just received this 240v heater today I ordered from Northern Tool. $69.99!
I picked up a socket, box, cover...got lucky and it's the correct one.
It's 5600 watts on high (23.3amps), and I plan on ceiling mounting it. It came with a 6ft. cord and outlet will be close to breaker box, like 42 inches away.
1) inside panel box is an unused 50 amp 240v breaker...that should be ok?
2) I bought a spool of 12/3 copper wire. Looking up that should be ok for 25 amps. I think less than 4ft...that should be ok?
3) it has a thermostat. Garage has a 125k btu furnace, but way away from where this is. I want this set at like 38F.
Working in that area I'll set it for 60.
4) I meant to buy 12/2...this is 4 wire 12/3. I'll run it in conduit. 4th wire just use for ground?
Thanks in advance.

 

[RNeumann]

Wire size is based on breaker size. It should get a 30 amp breaker and you should use 10ga wire. It will need 2 wires and a ground. I hesitate to say you need 10/2 as you can’t technically use the white wire as one of the 240v legs. You would need to change the color to black or red.

Undersizing the wire isn’t a good idea.....

That 240v circuit doesn’t have a neutral. So a 10/3 romex wouldn’t use the white wire.

 

[Fuddy1952]

Ok. I'll get 10 gauge 10/2 and a 30 amp breaker. Best to do it right! Thanks

 

[LouNY]

10 gauge is the correct wire with a 30 amp breaker, if you are going to use conduit you can pick up THHN or THW wire and not use romex.
You could get fancy and have a black, a red, and a green or two blacks and a green.

 

[homesteader13]

You actually want 10-3 wire for 220/240V (If you want it to code) With the new codes you have two Hots, one ground, and one neutral.
Black, leg 1 hot
Red, leg 2 hot
White, neutral
Bare or green, ground

 

[PILOON]

That's how I heat my garage also.
I have mine hanging from the garage door overhead track blowing slightly downwards.
Keep it set low just to keep temp above freezing and I crank it up when I want to work.
Keeps the place dry so tools don't rust and liquids don't freeze.
Going on about 12 years now.

 

[3Ts]

Since he doesn't need a neutral, it's my understanding that code allows the use of the 10/2 wire (Black, white, & ground) AS LONG AS the white wire is "relabeled" meaning he has to change it's color to either red or blue by wrapping it with colored electrical tape (at both ends). I am not a licensed electrician so this needs to be verified with one.

 

[CobyRupert]

You could use the 50 amp breaker if you want, BUT the wire has to be sized based on the breaker (not the fact the load only draws 23.3 amps). For a 50 amp breaker you need (2) #6 Awg conductors and at least a #10 awg ground (if you don't use the conduit for a ground conductor).

However, the minimum size breaker you can use has to be sized for 125% of the load (23.3 x 125%=29.1 amps), so a 30 amp breaker is O.K. Again, wire has to be sized for breaker so (2) #10 Awg conductors (w/ a #10 awg ground) is required. You can think of this as a 3-conductor #10 Awg; or a 2/c #10 Awg with ground, same thing (other than the colors that may be around the conductors). Or as Lou noted, conductors don't have to be a "cable", they can be individual wires in a conduit.

3Ts is correct. A white insulated conductor not being used as a neutral needs to be re-identified (taped) with a different color. The ground conductor needs to be identified with green.

 

[LD1]

Cant add anything. Just Echo what others said. And that is do NOT put 12ga on a 50a breaker.

10ga + 30a breaker and you are good

 

[Sigarms]

My only question is what kind of insulation do you have and what size is the garage if 112,000 BTU's won't keep the space at 60?

Also wonder what your electric rate is because running 23 amps on that portable heater on high is going to use some juice.

You couldn't just run some saddle collars and wrap some round wrapped pipe to take air where you need it?

I've got to ask, what's the wall stack for (duct blue arrow goes to)?