Hi,
I am installing two baseboard heaters in an additionn (two separate rooms). I will be running new wire and putting them on the same circuit. The heaters will be 48" 240V rated at 1000 Watts (4.2 amps).

My qestions:
-What size wire should I use (12/3, 10/3, etc.)?
-What should the amp rating of my circuit be (20, 30...)?
-Is in fact a 48" 240V heater enough to marginally heat 120 s.f. of well insulated room (average winter low/high is 20/45)?
Thanks,
Jesse

#12 wire will give you an ample margin. If the heaters don't have any 120 volt components, you only need to run 12-2 with ground. Can't say if 1000 watts will be enough, but the wiring will be heavy enough to add more if you have to. Use a 20 amp, double pole breaker.

Why do you only need to run 12/2 wire. Is a neutral wire unnecessary?
Thanks for your time.
Jesse

Kitchen ranges and dryers have timers and lights that need 120 volts. They must have the third wire as a neutral. A/C compressors, hot water heaters, baseboard heaters usually only have the parts that use 240 volts. Check the heaters you are buying. They should only have 3 terminals, the 2 ends of the heating element, and a ground. I was sort of hoping tkrussel would confirm my answer. He has much more experience in electricity than the rest of us here.

I agree with labman on this heater issue. Two hot legs and ground is all that is necessary with 220 volt base board heaters.

Why do you only need to run 12/2 wire. Is a neutral wire unnecessary?
Thanks for your time.
Jesse#12 should be enough.. if the instalation call for 2 hot you still have to put in the ground ( and it call for neutral you put in the neutral; still need a ground) most only call for 2 hot and ground... 1000 watt equal to 3400 BTU... you might want to add it up 1200.. the thermostat will turn it on and off, but with 1000 it will stay on all the time( IF YOU LUCKy 1000 may work)

Here is another question:

Everyone says that 240V baseboard heaters are more efficient than 120V?

Is a 48" 120V heater pulling 1000 watts at 8.4 amps really less efficient than the same size at 240V using 1000 watts at 4.2 amps?

Thanks for all your expert info!

Actually with electric heat it is KW in and BTU out. Electric heat is just about 100% efficient to start with. The only reason I can see that 220 volt baseboard heaters are better than 110 volt baseboard heaters is the 110 volt heater has to be about twice as long to get the same BTU taking up more space. Also electeic heat of the 220 type pulls on both legs of the meter helping to prevent a imbalance load on the electrical service.

Biggest advantage of 240 over 120 is on heavier loads where you can run lighter wire. On 12-2 at 240 you could go up to 4320 watts. With 120, half that. There is also slightly less line loss, which makes it that much more efficient.

first of all you should use 12/2 gauge wire then you should use a double 20 breaker... and a 1000 watt heater should be used in a room 10' x 10' and not any larger

Lee,

Hello and welcome to this site.

You chose to append to an item that is five years old.

Please do not do that as most of the items that are this old are ignored.

Either, open a new thead or withhold your answer for a more current item.