Two heaters combined 4500w

[krisway]

I'm stillin the planning stages. But is it safe to run two base board heaters (one on each side of my garage) one 2000w and the other 2500w. I will be running them with 10/2 wire off a 30 amp dbl breaker. And leaving the heater on 10 degrees for the winter months.

 

[Speedy Petey]

Yes, you are fine doing that.
#10 is a bit of a pain to work with, if breaker space is not an issue I'd run #12 (or even #14) to each one separately.

 

[jvitez]

4500 watts divided by 240 volts equals 18.75 amps, multiplied by 1.25 for continuous load equals 23.4 amps. The next standard breaker size is 30 amps, so yup, you're fine.

 

[Speedy Petey]

The next standard breaker size is 30 amps, so yup, you're fine.

Actually it's 25A.

 

[wyliesdiesels]

Speedy- what's the relevant code section for the 1.25 multiplier. Finally got my NEC book and would like to know what article/code section that's in. Thx!

 

[pattenp]

2011 nec 210.19 (a) (1) also 210.20

 

[wyliesdiesels]

Thx pattenp. I was gonna read that section when I realized I left my code book in my work truck so ill look tomorrow. Thx again!

 

[jvitez]

Hey Speedy: 25 amp breaker? Cool. I just did some Googling and who'd uh thunk it: they exist! Learn something new every day. Thanks!

 

[Speedy Petey]

2011 nec 210.19 (a) (1) also 210.20

And related directly to fixed electric heaters: 424.3(B)