Joining two baseboard heaters

[krisway]

I have a base board heater in my garage, and would like to add a second one. The wires are in my attic, is it okay to use a junction box and tie in my second heater? OR, do I have to join the heaters end to end? I want the heaters on opposite walls, and would like to be efficient in running wire.

If the two heaters are 2000w each, is 12/2 wire okay, hooked up to a 30 amp double pole breaker? Or do I need 10/2 wire?

 

[VHF]

2000W/240V = 8.3A
8.3A x 2 = 16.6A

#12 wire must be on a 20A (or smaller) breaker. For a continuous load, the rule is that connected load should not exceed 80% of of the breaker. 20A * 80% = 16A. So unfortunatly, you are just over the permissible continuous load for a 20A breaker with 12/2 wire.

A 30A breaker allows up to 24A continuous, but requries #10 (or larger wire).

So either put both your heaters on a 30A breaker using 10/2 wire, or put then each on their own 20A breaker using 12/2 wire. Don't forget to recolor the white conductor to red for the second hot leg in a 240V application.

Doesn't matter if they are joined end-to-end or at a junction box in the attic, but if using a 30A breaker the entire circuit must be #10 wire.

If it wasn't a continuous load like electric heat or lights (or if you heaters were slightly smaller) then you could put both an a single 20A 240V circuit wired with 12/2.

Addendum--Check for a data plate on your heaters. If it lists current as 8A (not 8.3A), then you would be OK putting them both on a single 20A circuit wired with 12/2.

 

[krisway]

2000W/240V = 8.3A
8.3A x 2 = 16.6A

#12 wire must be on a 20A (or smaller) breaker. For a continuous load, the rule is that connected load should not exceed 80% of of the breaker. 20A * 80% = 16A. So unfortunatly, you are just over the permissible continuous load for a 20A breaker with 12/2 wire.

A 30A breaker allows up to 24A continuous, but requries #10 (or larger wire).

So either put both your heaters on a 30A breaker using 10/2 wire, or put then each on their own 20A breaker using 12/2 wire. Don't forget to recolor the white conductor to red for the second hot leg in a 240V application.

Doesn't matter if they are joined end-to-end or at a junction box in the attic, but if using a 30A breaker the entire circuit must be #10 wire.

If it wasn't a continuous load like electric heat or lights (or if you heaters were slightly smaller) then you could put both an a single 20A 240V circuit wired with 12/2.

Addendum--Check for a data plate on your heaters. If it lists current as 8A (not 8.3A), then you would be OK putting them both on a single 20A circuit wired with 12/2.

Thank you for your answer. I will run 10/2 wire from the 30amp breaker to both 2000 watt heaters and have the heaters joined using a junction box in the attic.

If I'm heating my 16x36 garage at 10 degrees for the winter months, would this be considered continuos load?

 

[Alchymist]

Electric heaters are considered continuous load.

 

[pattenp]

Thank you for your answer. I will run 10/2 wire from the 30amp breaker to both 2000 watt heaters and have the heaters joined using a junction box in the attic.

If I'm heating my 16x36 garage at 10 degrees for the winter months, would this be considered continuos load?

Yes. Continuous load is where the full current could be expected to run for 3hrs or more.


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[krisway]

Thanks guys.