Unit heaters

[toomunsch]

Can 2 3kw 1ph 208v heaters be installed on 1 circuit? I remember seeing something about 30a max breaker in 424 of NEC.

 

[JFletcher]

Can 2 3kw 1ph 208v heaters be installed on 1 circuit? I remember seeing something about 30a max breaker in 424 of NEC.

No because each heater draws 14.4A, and 28.8A is too much as a continuous load on a 30A breaker. Heating loads are considered continuous so you are limited to 24A (80%) on a 30A breaker. You'll need 2 20A circuits.

 

[Dennis Alwon]

Are the units listed at 3kw for 208v or at 240V. This would make a difference

 

[kwired]

Can 2 3kw 1ph 208v heaters be installed on 1 circuit? I remember seeing something about 30a max breaker in 424 of NEC.

Correct on the 30 amp - see 424.3. Circuits supplying multiple units are limited to 30 amps, though if it is an infrared heater in other then dwelling, it can be on 50 amp circuit.

 

[toomunsch]

I don't have the guts yet but I think they are just resistive heaters. Thx for the input

 

[JFletcher]

Are the units listed at 3kw for 208v or at 240V. This would make a difference

You're correct. If they are 3kw @ 240V, they will draw 10.8A ea on 208V, tho the output will be reduced to ~2.3kW. Both could be on one 30A circuit.