FAQ to Changing an Electric Dryer Power Cord from a 3-Prong Plug to a 4-Prong Plug
November 11, 2009
On August 17, 2006 I wrote Changing an Electric Dryer’s Power Cord from a 3-Prong Plug to a 4-Prong Plug. The purpose of the article was to teach everyone that the ground and neutral wires need to be separated when changing your dryer to a 4-wire configuration.
I’m not a dryer repair expert. I’ve installed several dryer cords and repaired dryers for myself, friends and family, but that’s the extent of it. If you have a dryer repair question, then I recommend Appliance Parts Pros – They offer live help, a repair forum, part photos, diagrams, same day shipping and you can return any part.
I think the number one question that everyone asked was what to do with the existing ground wire?
A: If you had an existing ground wire that was not connected to the neutral, then leave it connected in it’s current position. You may also connect the ground wire from your 4-wire cord to this same ground screw.
All that we are trying to accomplish here is to separate the ground from the neutral. All ranges and dryer ship from the factory with the ground and neutral connected. If you change your range or dryer to a 4-wire configuration, then the ground and neutral connections need to be separated.
Q: This article is very helpful. However, my husband did those exact same steps…the only problem is that our dryer has no heat. is this something that has to do with switching out the cords?
A: It could be and it could just be a coincidence as well. Are all of the connections tight and connected properly? If so, then I’m not sure. My guess would be a bad or broken heating element. Check with the guys at appliance parts pros. I think they would be more helpful.
Q: I have an Estate dryer and there is a black, red, and white connection and the new cord has a green ground wire. The external ground screw has a white wire running to it (I’m changing from a 3 prong cord) and the green wire on the new cord won’t reach it. What am I doing wrong?
A: I don’t think that you are doing anything wrong. Most times the wires are not stripped long enough from the factory. Just strip off a couple more inches of the outer jacket on the cord and push your cord further into the connector. This should lengthen your wire and solve your problem. Make sure the dryer is unplugged before you begin working on it.
Q: I switched my 3-prong plug to a 4-prong plug today. The only thing that I am still not sure about is my ground wire that was connected from the dryer, goes all the way back into the dryer. I unscrewed the old ground wire and connected the green ground wire from the 4-prong plug onto the ground wire screw. Now, I have this open prong from the old ground wire just hanging there. What do I do with it? Should I cover the end of the ground wire with an electric wire cap or electrical tape?
A: You need to reconnect this wire. The only thing that needs to be disconnected is the bonding strap that is on the neutral (white) terminal. Sometimes this is a ground wire instead of a bonding strap. If there is a ground wire connected to your neutral terminal, disconnect it and connect it to the ground screw on the dryer’s frame. Make sure the dryer is unplugged before you begin working on it.
Q: I am a little confused as with my 3-prong plug, there was a green wire that was grounded to the dryer. When I installed my 4-prong plug, I replaced this green wire with the green wire from the 4-prong plug. What am I supposed to do with the green wire that was grounded to the dryer with the 3-prong plug? It is just hanging there now. The diagram with the dryer shows this green wire attached with the white wire to the center terminal. Is this what I should do?
A: If the green wire was already connected to the ground screw on dryer’s frame, then put it back there. The only wire or strap that needs to be disconnected is the one bonding the neutral terminal to the dryer’s frame. This is the terminal with the white wire and typically in the center.
Q: Okay, I tried this on my son’s dryer in his apartment. The problem was the 3-prong wires were all the same gray color. We put it on as we thought it should be layed out and when we plugged it in it blew out the power in his whole apartment. We had to find the breaker box on the whole apartment building to get the power back on. Do you think it would work if I just rotated the wires the opposite way? This made me a little nervous. Or maybe is there another way to tell the wires?
A: If you are trying to determine which wire is which on the 3-prong cord, then the 2 outer wires are your hot wires and the center is the ground. If you are trying to determine which wire goes to which terminal, then the terminals should already have color coded wires which go into the dryer. Typically, the terminal blocks are 3 position. The outer terminals are typically the hot wires and the center terminal is typically the neutral wire.
Q: We moved into a brand new home that has a 4 prong outlet. We purchased a 4 prong plug to switch out our 3 prong plug but it didn’t fit. We took a picture of the outlet and showed it to the hardware store and they sold us a plug that looked like it would work but it doesn’t. How many different 4 prong plugs are there?
A: There are several different configurations. What you need to do is look at the receptacle (outlet) to determine what you have. On the face of the receptacle you should be able to find the NEMA configuration, voltage and amperage ratings. Your receptacle should be a 14-30R, 125/250 volt @ 30 amps. You need a 14-30P plug.
Q: How about doing the reverse? My dryer has 4-prong wiring and the receptacle has 3 prongs. I know white-white, green-green, but I only have one extra line for the black and red from the new light gray cord. Any help before fireworks would be helpful!
A: I also wrote How To Change a 4 Prong Electric Dryer Power Cord To a 3 Prong Electric Power Cord. This article should help you out.
Q: I have a Maytag de212 dryer and was attempting to convert my 3-prong adapter to a 4-prong using your above instructions. I hooked it all up like shown, but nothing happens when I hit the start button on the dryer. Is it possible that I have a faulty cord? I plugged it up, checked the breaker to make sure it was on, so I just don’t get it now.
A: To determine if your cord is bad, simply check for voltage at the terminal block in the dryer. If you test between the black and red wires you should get approximately 240 volts. If you measure between the black & white, red & white, black & green and red & green you should get approximately 120 volts.
Q: I understand you pictures on how to change the cord on my dyer, however the wire on the far left side is green not red on my dryer, the middle wire is white and the far right wire is black. If I connected the 4 prong as instructed in the picture it would put the red wire on top of the green wire. What should I do?
A: It sounds like your dryer is only 120 volts. Do you have a gas dryer? DO NOT connect the red wire to the terminal with the green wire, this will create a short circuit and possibly damage your dryer. Check the voltage rating on your dryer to ensure it is 240 volts.
Q: Thanks for your instructions!…quick question….going from 3 prong to 4 prong…my 3 prong had a bonding strap attached to the white wire….where do i attach the green wire from the 4 prong? i don’t have a green screw attached to the dryer frame as illustrated in your picture above.
A: There should be a spot somewhere with the ground symbol and just missing a screw. You can get a green ground screw at your local hardware store.
Q: Thanks so much for the instructions!! I only have a minor question or two. There is a small white wire already attached to the neutral terminal. Can I put my white wire from my plug directly on top of that and use one screw or do they have to be separated?? If they do have to be separated, what type of metal screw do I use (I am short one if they need to be separated)? Okay, three questions…my connector is not doing it’s job because the cord hole is not large enough to insert the connector to stabilize it. Do I really need this or can it just hang?
A: Did you drop one of the screws down the back of the dryer? Check with Appliance Parts Pros to see if you can get another. You shouldn’t place both wires under the same screw. The wires can loosen creating more problems and possible a fire.
The cable (wire) needs to be in a connector. This will prevent the wires from being pulled out. This will also prevent the cable from becoming damaged by rubbing on the metal hole where it enters the dryer.
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