Wiring An Electric Fireplace For 240v.?
After wiring my cct brkr for 240v I had to have a repairman come in to see why my fireplace did not produce heat. He found that with the 4 wire connection, recommended, I was getting 117v from red to white and 117v from black to white. The problem being is that I also only read 117 from black to red, where it was expected to read 230-240v. Checked the wiring for my dryer which is also 240v, 4 wire and it did read 240v from black to red. Why do I only get 117 when I should be getting 240v?
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October 25, 2009 @ 10:45 am
Justwondering and Duncan are right. If you are getting 117V to ground on both legs and 0V difference between them, both breakers are on the same side of the electric service. In a residential single phase service, there are two wires that come out of the transformer from the electric company plus a common ground. Each of those two wires come out of the transformer 180 degrees from the other on the sine curve that alternating current can be represented with. Inside of your electric panel, you’ll see a metallic buss bar that the circuit breakers are clipped or bolted to. If you look closely (don’t EVER touch this with your body or anything that conducts electricity), you’ll see that there are in fact two buss bars. One of them is connected to incoming line 1 by a lug connected to the bar and the other is connected to incoming line 2. The problem that you’re having is that both the black wire and the red wire from your fireplace are connected to the same incoming line. This is a common do-it-yourselfer mistake and is easily fixed.
First… are there any open spaces for breakers in your electric panel? If there are, all you have to do is buy a 2 pole circuit breaker of the same type as the original breakers that came with the house. Circuit breaker types are indicated by 2 or 3 letters marked on the circuit breaker. If this is a fairly new house, it will probably be a MP-T, QP, QO, or HOM type breaker. A 2 pole circuit breaker is completely different from a tandem circuit breaker. While they both have two separate handles, tandem circuit breakers are usually not connected at the handle and usually feed both circuits from the same incoming line on the electric meter. 2 pole circuit breakers, on the other hand, are connected so that they both get turned on and off at the same time. They also connect each individual handle to a different incoming line on the electric meter. Unless your electric panel is at least 40 years old and one of a few rare types, a 2 pole circuit breaker should be twice as wide as a regular single pole circuit breaker.
Now… if you don’t have any open spaces for breakers in your electric panel, you’ll have to put in some tandem breakers. Look at the two circuit breakers directly above the one that you installed for your fireplace. Hopefully, they’re single pole circuit breakers that say 15 or 20 on them. Go to the store and buy either a 15/15, 15/20, or 20/20 tandem circuit breaker of the correct type. Connect the two circuits that you looked at earlier to the tandem breaker next to the appropriate rating. Install the tandem breaker into the space occupied by the top breaker of the two that you’re working on and remove the bottom breaker that is now not connected to anything. BE VERY CAREFUL WHILE YOU ARE INSTALLING BREAKERS TO NOT TOUCH ANYTHING METAL WITH ANY PART OF YOUR BODY. Keep your fingers only on the plastic part of the circuit breaker and don’t let your fingers or any rings or jewelry touch any metal part of the electric panel. You will now have an available open space and can proceed as described above. As always, do not attempt anything that you feel you are not qualified to safely do. An electrician or qualified handyman shouldn’t cost more than about $150 to fix this problem for you, so call one if you’re not sure.
October 25, 2009 @ 9:20 pm
You have to check the complete circuit. The double pole circuit breaker that you have for the 240V from the panel should be the first thing that you check (power source out!). It seriously sounds like you dropped a lag. The voltage may show the same for each black and red, by inductance but one side will not have the current flow (no amperage) to one. The percentage drop to 117 is not outside of normal ranges, but may indicate bad connections. If all else fails hire an electrician. How did you wire it? CB?
October 26, 2009 @ 1:00 am
the breaker may be going bad if you read 117 between the black and red,or someone has wired the breaker wrong 240 should be hooked to a two pole breaker if its a heavy load like a stove the breaker should be 50A you may have a wire lose also.why didn’t the electrician fix the problem while he was there?
October 26, 2009 @ 1:43 am
Ok …Easy problem to fix but you got to listen up…
Turn All Power off if your not that Experienced..
On your Circuit Breaker (In the fuse box) that runs the Firebox.
BOTH the RED & BLACK wire should be connected to the Breaker…Your Breaker has to be DBL.Pole, Single throw.
In other words two SIAMESED breaker in one NOT SEPARATE (THIS MAy BE Your Problem)
then the WHITE and GREEN should be on the Ground Bar…
That’s IT……Let me know how it goes…
October 26, 2009 @ 5:00 am
I’m gonna take a stab at this – did you get a “thin” 2 pole breaker because there was not 2 spaces open in the panel? to get 240 you have to draw 110/117 from different legs of the service – they can’t be on the same slot in the breaker line up. You could try removing the breaker above or below and moving this double breaker up 1/2 space.