Elec Baseboard Heating - Confirm for installation


Old 11-19-05, 04:39 PM
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Question Elec Baseboard Heating - Confirm for installation

1 - I would like to install 5 baseboards heater.
I do have left a 30 amps - 240 v box in my panel.
So I suppose that I 'am abble to wire about 7200 watts?
Using the rules amps = watts/volts,
so watts = amps x volts
2 - I'am wondering if in the case that I wire all the baseboards on one circuit, I'll be abble to install severals wall mounted thermostats or should I use built-in thermostat.
I have the feeling that a wall one should shut off a part of the circuit and make the following baseboard out of power, and if those are in a different room, they will not be abble to work.
Or may I wire two or three differents circuits from the same 240v-30 amps box.

Thank for all your help...

Last edited by dufferin; 11-19-05 at 04:48 PM. Reason: addition
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Old 11-19-05, 06:00 PM
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I'm confused. The size of your main breaker or panel ampacity does not limit you to the size and number of breakers you can put into it, only the physical number of spaces (which can be sometimes extended with special thinner tandem breakers.) What DOES matter is a load calculation based on which devices are used at the same time and their duty cycles.

What is the wattage required by each of the heaters you are installing?
Old 11-19-05, 06:15 PM
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If you stay with the 30 amp breaker you can have up to 30 x 240 = 7200 watts of heating on that circuit. However, you could use a 40 amp breaker and have 40 x 240 = 9600 watts on the circuit.

The wattage you need is determined by the size of the area to be heated.

All the units in one room should be controlled by a single thermostat, unless it's a very large room.

How you run the wires is up to you.
Old 11-19-05, 06:53 PM
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As I am unlicensed, this is just my opinion...

...that if the poster goes with the double 30 breaker that he should be aware to wire all the heaters with 10 gauge wire. If 12 ga. were used and the entire circuit overloaded, the breaker may not know to trip.

And just for a way were people can calculate out baseboard heater needs, or whatever...you can figure about 200 watts per foot of heater.
Old 11-19-05, 07:16 PM
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I am confused too
My wattage is 4300 for all.
I don't have more room to put another breaker. I do have an 100 amp panel.
but I do still have 30 amp without anything plug on it.
I want to install 2 heater (total of 2500 W) in the living room, 1 in each bedroom (750 W ea) and 1 in the bathroom (300 W).
And as you can understand I am not that used with electric configuration.
Old 11-19-05, 07:30 PM
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It will not be a simple wiring task for a DIY'er to put all these on one circuit. Unless you are quite versed in home wiring.
You will need to feed a wall thermostat, then out to another room, and from the load side of the t-stat to the heater. And so on to each room.
Old 11-19-05, 07:51 PM
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As a conservative rule of thumb, a breaker should not have a continous load more that about 80% of full load. So, a 30 amp circuit should not have contunuous loads over about 24 amps, = 5760 watts. You should use a 40 amp breaker, which needs larger than #10. If would be better to use more than one circuit, possible a combination of 20 and 30 amp circuits, as appropriate.

It is difficult sight unseen to do a heat loss recommendation. For a VERY ROUGH estimation, you could look at 10 watts per square foot, increasing that to 12 or 15 if in a very cold climate or lots of glass.
Old 11-19-05, 07:58 PM
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A 40 amp circuit is not allowed for fixed electric heating in a residence.
For two or more heaters, only 15, 20, 25 or 30 amp circuits.
Old 11-19-05, 08:53 PM
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thank you,
all the answers are usefull.
Skill improvment night.

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