How To Change A 4 Prong Dryer Cord And Plug To A 3 Prong

Congratulations! You've just moved into your new home, the new drapes are up and the washer and dryer are ready to be into place. But wait! The dryer cord won't plug in - the dryer cord has four prongs but the wall receptacle only has three holes! What's up with this?

What's up is that in 1999 the National Electric Code instituted a change, requiring that all new dryers and home dryer receptacles to have 4 prongs instead of the older 3 prong style. That fourth prong is a ground wire and is there for better electrical safety.

Now, it would be convenient if there was a dryer cord adapter that you could plug into that 3 prong receptacle and then plug your dryer into it, but there isn't. You will have to change the dryer cord to make it fit. On the plus side, these cords are readily available, fairly inexpensive and the task isn't a very hard one. A screwdriver and a pair of pliers from your homeowner tool kit will do the job, although some nut drivers would be nice.

If your dryer cord and outlet are backwards from this (you have a 3 prong cord and a 4 prong outlet) you are on the wrong article. Use the link here to an article on changing a 3 prong cord to a 4 prong cord.

Begin by unplugging the dryer. There is high voltage (240 volts) inside that will give a very nasty shock and can kill. Make sure there is no chance of this by unplugging the dryer before proceeding any futher.

There is a connector that holds the dryer cable to the wall of the dryer so that it doesn't pull out. While there are several styles, the most common has two screws on the outside that squeeze the wire; loosen these screws so that the wire can slide out of the dryer.

Remove the cover plate from the wire terminal block, exposing the wires inside. Note where each color of wire is terminated; normally red and black wires on on the outside of three terminal screws, the white wire is on the center screw and the green wire goes to the frame of the dryer. Remove each wire from the screw or stud holding it, making sure to save all nuts or screws.

Work the wire out of the connector holding it to the wall of the dryer and set it aside for possible future use; you never know when you might move again, and Murphy's Law says it will be back into a home with a 4 prong dryer plug!

Once the four wire cord is removed it is time to install the new three wire cord and plug. Work the wire through the connector, but do not tighten it yet. The red and black wires go to the outer two terminals (in the photo the dryer wires are black and blue) and the white wire is to terminate on the white dryer wire in the center of the terminal block. While the red and black wires are interchangeable, the white wire is not; make sure it goes to the center terminal, where the old white wire was.

There is no green ground wire in the three prong cord. In place of that wire a ground strap or short piece of #10 wire (preferably green) must be installed. One end should go to where the green wire on the old cord went and the other end to the terminal where the white wire is terminated. Do not ignore this step! This ground wire or strap is the only thing that grounds the dryer; if there is a problem later the frame may become energized and present a huge shock hazard. Make sure that there is a "jumper" installed between the range frame and the white wire.

The photo shows a metal strap installed; it goes from the white wire, down the side of the terminal block and is screwed to the dryer frame. If this strap is not available (and it usually isn't) purchase a one foot piece of #10 green wire, strip an inch from each end, and install that wire between the white wire and the frame where the old green wire went. With the wires all terminated, tighten the connector on the outside of the dryer that holds the cable securely.

It is wise to turn the power off at this point, just in case something has been wired wrong. With the power off, plug the dryer into the wall outlet and turn the breaker back on. Test the dryer for proper operation and you're done. Congratulations on doing your own home repair job - it wasn't so bad, was it? Ready to install a new light fixture or to replace some of those sloppy wall outlets that won't hold a cord in? How about a new hardwood floor? Whatever you need, we probably have instructions for it; if you don't see what you want, let us know. We'll do what we can to help out.