wiring for electric baseboard heater


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Old 11-19-07, 02:54 PM
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wiring for electric baseboard heater

I have just installed a 4ft 1000watt 240v baseboard heater, in a upstairs bedroom.

It is running on a dedicated 20amp double pole circuit with 12/2 cable running from the circuit breaker to a junction box in the wall. And then split out to the heater. (Eventually I plan to run another heater off it, but right now that is the only thing connected to the 20amp circuit.)

I only had enough 12/2 wire to reach the juction box, so I used 14/2 to run to the heater.

My question is wether that is safe or not? I am worried about the 14/2 getting too hot running off the 20amp 240v circuit. Does it sound safe or should I replace the 14/2 with 12/2? thanks
 
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Old 11-19-07, 03:00 PM
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You need to replace the 14-2 with 12-2, or you could change the breaker to a 2 pole 15 amp.
 
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Old 11-19-07, 03:40 PM
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will a 15 amp provide enough juice?
 
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Old 11-19-07, 05:24 PM
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Be safe - keep the 12-2

1) Techically a code violation - You should not mix 14 and 12 gauge on a 20 amp circuit - so ditch the 14/2.
2) I would not change the breaker to 15 amp especially if you are going to add more heaters. Changing the breaker is more difficult than adding the correct wire ( you can use the 12/2 wire left when you add the extra heater)
3) Your 1000w heater will draw 4.2 amps - you should learn how to calculate the loads if you are going to continue with heater installs
 
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Old 11-19-07, 05:27 PM
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At full power with the heaters, I'm calculating a 16.66 amp load rating. A pro can double check my calculations.

total wattage / volts 4000/240 = 16.66
 
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Old 11-19-07, 05:40 PM
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The 1000 watts is the total wattage of the 4 foot unit, not 1000 per foot. A standard heater runs 250 watts per foot.
 
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Old 11-19-07, 05:41 PM
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He only has one heater of 1000 watts. It is 4 feet long, not 4 1000 watt heaters
 
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Old 11-19-07, 05:52 PM
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It is NOT a code violation to mix 14 and 12 gage wire on a circuit, provided that the breaker is only 15 amps.

That being said, it is NOT a good idea to have 12 gage wire at the panel, 15 gage wire downstream even if the breaker is 15 amps. Someone someday will think the breaker can be up-sized to 20 amps, when it cannot.

Replace the 14-2 with 12-2. Make sure that the junction box is permanently accessible. You must be able to remove the cover and get at it at any time, without having to remove drywall.
 
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Old 11-19-07, 05:53 PM
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Originally Posted by ebarrett25 View Post
will a 15 amp provide enough juice?
A 240V 15A circuit may supply up to 2880 watts of baseboard heaters.

A 240V 20A circuit may supply up to 3840W of baseboard heaters.

You need to either replace the 20A breaker with a 15A or replace the 14/2 with 12/2. I recommend that you replace the 14/2. This will avoid the later confusion of someone seeing #12 wire in the panel and incorrectly thinking that it would be okay to upsize to a 20A breaker.
 
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Old 11-19-07, 07:03 PM
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Originally Posted by joed View Post
He only has one heater of 1000 watts. It is 4 feet long, not 4 1000 watt heaters


Yikes, I must really need sleep...
 
 

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