DIY Chatroom Home Improvement Forum (http://www.diychatroom.com/)
-   Electrical (http://www.diychatroom.com/f18/)
-   -   Electric heaters, how many circuits? (http://www.diychatroom.com/f18/electric-heaters-how-many-circuits-40247/)

 Richo 03-13-2009 02:14 PM

Electric heaters, how many circuits?

I am looking to install 2 1500W 240V electric heaters in a basement. I'm going to use 12 gauge wire for each heater but here's my question:

I'm aware that 12 gauge is good for up to 20 amps @ 120V but if you are using 240V, does that mean you can go up to 40 amps and run both of these heaters off the same circuit/wire? And if so, would I use a 40 amp double pole breaker?

If they need to be run on separate circuits, do I just need a 20 amp double pole breaker for each heater or 40 amp?

 47_47 03-13-2009 02:25 PM

12 gauge is good for 20 amps.
1500W/240V= 6.25 A each
Use 12-2, put them on one circuit with a double pole 20.
Just make sure your thermostat can handle the wattage.

 Richo 03-13-2009 02:41 PM

Thanks! I was hoping that I could save on extra length of wire and an extra breaker. I appreciate your help!

 47_47 03-13-2009 02:56 PM

Just to be complete, 12 gauge is good for 20A, 80% continous (16A). Your total amperage is 12.5 and you can put 16 on this circuit. Do these heaters have an internal thermostat? If they don't I recommend running your wire to the first stat and pigtail it to a second stat. This way you can operate the heaters independantly.

 InPhase277 03-13-2009 06:58 PM

Quote:
 Originally Posted by Richo (Post 244183) I am looking to install 2 1500W 240V electric heaters in a basement. I'm going to use 12 gauge wire for each heater but here's my question: I'm aware that 12 gauge is good for up to 20 amps @ 120V but if you are using 240V, does that mean you can go up to 40 amps and run both of these heaters off the same circuit/wire? And if so, would I use a 40 amp double pole breaker? If they need to be run on separate circuits, do I just need a 20 amp double pole breaker for each heater or 40 amp? Thanks for your help.
You have been given good advice already, so I'll just clarify a little theory for you. Amps heat a conductor the same regardless of the volts. A #12 conductor is good for 20 amps period, 12 V, 30 V, 120 V, 600 V.

 Richo 03-13-2009 08:50 PM

Each heater will be controlled by its own line voltage thermostat so I will want them to run independent of each other.

I had a simple electrical class many years ago and learned about Ohms law, etc...just had been a while so I wanted to make sure I had it right before I proceeded.