How to Wire a 220 Volt Heater Circuit to Sub Panel
Electrical Circuits Question: I'm having a problem with wiring a 220 volt heater circuit. I installed a 20 amp double pole breaker in my panel, and I ran 12/2 wire with a ground to the outlet.
Installing and Connecting a 220 Volt Heater Circuit to a Sub Panel
220 Volt Heater Circuit Installed to Sub Panel
I'm having a problem with wiring a 220 volt heater circuit.
I installed a 20 amp double pole breaker in my panel, and I ran 12/2 wire with a ground to the outlet. On the breaker, I connected the white and black wires to each pole, and connected the bare copper wire to ground.
At the outlet, I connected the bare copper wire to ground (the green terminal), and I connected the white wire to one side, and the black wire to the other.
When testing with a volt meter, if I put one terminal on ground and one terminal on either pole, I get 110 volts.
If I put both terminals on the poles, I get nothing. Aren't I supposed to be getting 220? The bottom line is that the 220 volt heater that I bought isn't working when I plug it in. The heater is single phase, so I didn't think it mattered which side I connected the black and white wires to. Regardless, the heater still doesn't work if I reverse them. At first, I thought the heater might be defective, so I exchanged it for another one, but the new one doesn't work either. Obviously, there's something wrong with the way I wired the outlet. Can you help?
Thanks- Patrick D.
Hi Patrick - Great Electrical Repair Question!
It sounds like the two breakers are attached to the same buss, so your only getting the 110 volt reading. This can happen if you are using a Twin Breaker. If this is the case then you need to use a full size 2-pole breaker. If you are using a full size 2-pole breaker then for some reason your panel is not getting both hot legs. You need to check this and let me know what you find. Check anywhere in the panel across two hot legs to see if you get a 220 volt reading.
If you don't get a 220 volt reading you'll have to find out what feeds the panel you are at and see if it is wired right or there may be another problem. We wont get into that right now, lets just take it one step at a time and check the panel where the heater circuit originates from. From: Patrick D. Ok, we're on the right track. I'm wiring to a sub panel that's in my garage and I've attached a picture of it. If I take my volt meter and connect it to the red and black supply wires, I'm getting 220 volts
If you look at that 20 amp double pole breaker on the right, that's what I'm wiring my outlet to. If I touch the volt meter leads to each pole of the breaker, I get nothing. One lead to a pole and one lead to ground, I get 110 on each pole. From: Patrick D. Ok, I killed the power to this sub panel before I started messing around in it. When I bought this double pole breaker to do this little project, I noticed that it only had one metal clip at the bottom, but the whole box of breakers where I bought it were like this, so I didn't think much of it. Is this normal? I've attached a picture of the panel with the breaker out as well as a picture of the back of the breaker.
Hi Patrick, I looked at the pictures closer and I think I see the black wire loop up and then down into the right hand lug - so if this is the case it is ok. Then from the looks of this panel you may only be able to have one 2-pole breaker that actually gives 220 volts and I'll bet that it will be the center two spaces. You would know this by pulling out the two center breakers and see that the busses are separated. So in this case what you need to do is careful pull the 2-pole breaker and reinstall it to the center area of the panel. After you do this you will have the 220 volts necessary for your heater circuit.
Be sure to turn off the power before you do this!
From: Patrick D.
You da man!
Attached is a picture of the panel with all the breakers out. I put the double pole breaker right there in that middle spot, and viola! It works!
Thanks for all your help.
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