Wiring an electrica baseboard heater(s)


Old 09-27-07, 08:42 PM
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Wiring an electrica baseboard heater(s)

I'm going to be (pulling) wiring for 2 electric baseboard heaters with 1 thermostat. Please let me know if this is the correct sequence.

service panel --> thermostat --> electric baseboard heater #1 --> electric baseboard heater #2.

The service panel will be a 20 amp double pole breaker.
The romex wire will be 12/2.

I have not purchased the heaters yet, so if this is a concern, please let me know. Also, the room sizes are 272 sq ft and 384 sq ft. Each heater will be located below a window.

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Old 09-28-07, 12:04 AM
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Your wiring plan is fine but you have not given us the necessary information in order to tell you if your overcurrent device and branch circuit conductors are sized correctly.

Remember you are going to operate 2 baseboard heaters so that will double your load on the circuit versus 1 baseboard heater.

In order for us to tell you if the 20 amp branch circuit is correct, you will need to tell us the wattage or amperage of these 240 volt baseboards. I say 240 volt because you mention a double pole breaker. With this information we can tell you if your plan will work and be safe.

Old 09-28-07, 07:35 AM
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From what I know so far, the 2 heaters that will be on 1 circuit will be 240 volts. Their respective watts will be 1000 and 1500 for a total of 2500.
Hope this helps.
Old 09-28-07, 08:31 AM
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My only concern is you said room sizes....you planning on working both baseboards from a single thermostat which will limit your control per room.

My advice would be to get (2) thermostats....bring your feed to the first one and then feed the second thermostat so that you have a feed to each thermostat...then feed each baseboard accordingly....allowing you to control the heat individually in each room....and you will only pay for the additional box and thermostat....

As for the circuit if you are dealing 2,500W and 240V then you should be fine.

Figured I would also add how to calculate the amount of baseboard needed...

To do this you need to measure the length and width of the room. Multiply these measurements together and then multiply that number by 10. For example, if your room is 10 feet wide by 10 feet long your formula would be (10′ length x 10′ width) x 10 = 1000. For this example you need 1000 watts of electric baseboard heat to properly heat this room. A 4 foot baseboard heater is 1000 watts.

So I would venture to say based on your numbers your rooms are larger than 10 x 10...more like room # 1 15' x 18' = 270 x 10 = 10.8 so you would need atleast a 10' ( 250w per foot ) in the smaller room....and the other would be based on what you put 19' x 20' = 380 x 10= 15 ' of baseboard to heat that space.....

So.......just keep these things in mind......
Old 09-28-07, 02:23 PM
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I will be using multiple electric baseboard heaters wired to one theromstat. I'm not an electrician, but I believe you've described a serial circuit. The heaters I'm using require a parallel circuit. Thus my advice is to understand the wiring requirements for the heater before pulling the wire.
Old 09-28-07, 02:50 PM
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His wiring is fine. He is talking about two heater, I believe in the same room. It is both typical and proper for these to be on the same thermostat.

While they are in parallel electrically, they are usually physically wired in series.
Old 09-28-07, 03:15 PM
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Racraft, is correct, the ckt. is parallel.

The heater itself is series, the elliment creats resistance and that is where the heat comes from.

Your scheme looks fine. As long as your calcs will allow that ckt size.
Old 09-28-07, 03:21 PM
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What I meant by in series is that the wiring typically goes from the thermostat to the first heater to the second heater. Each heater sees a full 240 volts.

I am referring to the same way that lights are wired in series. Each light see a full 120 volts, so the lights are in parallel, but the wiring goes serially from one light to the next to the next.
Old 09-28-07, 03:58 PM
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Thanks for the help/comments and also for the re-assurance!

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