Changing A 3 Prong To 4 Prong Dryer Cord And Plug
My dryer cord has 3 prongs but the receptacle needs 4 prongs!
So you've finally moved into your new home and gotten the dryer wrestled into place. The vent is hooked up, ready to go, but the cord doesn't fit the the wall receptacle! Your dryer has only 3 prongs, but it needs 4 prongs to fit, (If your dryer has 4 prongs and needs to have 3 prongs, you are on the wrong article; try the one about changing a 4 prong dryer cord into a 3 prong cord). What's up with this?
In 1999 the National Electric Code began requiring all dryer receptacles to be the 4 prong type for increased safety, but homes built prior to that time used the older 3 prong variety. If you are moving from an older home into a newer one you will likely find that the dryer cord won't fit.
While it would be very nice if there was a simple 3 prong to 4 prong dryer cord adapter that could be purchased and used that isn't the case. The only real way to fix the problem is to purchase a new cord and install it on the dryer. This is not a real problem; most homeowners with even a small homeowners tool kit can install a new dryer cord. In most cases a screwdriver and possibly a pair of wire strippers will be all that will be needed. A pair of pliers or a nut driver set should be the only additional tools required.
Typical Dryer Cords and PlugsClick thumbnail to view full-size
Removing the old 3 prong cord.
UNPLUG THE DRYER BEFORE CONTINUING! If the dryer is unplugged there is no need to even check for voltage at the dryer, although a non-contact voltage detector will accomplish this if you want to be extra safe. Pull the dryer out until you can easily work on the back.
The cord will enter the dryer (or at least it should) through some kind of connector to prevent strain on the screws where the wire is terminated. Loosen any visible screws on this connector and remove the plate that covers the wire terminations. If the old wires are colored, note where the white wire ends.
Unscrew the fasteners holding the wire to the terminal board and remove the wires. Pull the old cable out through the connector and save it in case you ever move back into a home with a 3 wire dryer cord.
There will be a metal strap or wire fastened to the place where the white wire was and going to the frame of the dryer. Remove this strap or wire and once more save it for possible use in years to come. Take note of where this strap is screwed to the frame; one of the wires on the new cord will go there.
Removing the 3 Prong Cord and Plug
Dryer cords from Amazon
Installing the new 4 prong cord
First, make sure that you have the right new cord. A range cord, for a cooking range, looks very similar and also has 4 prongs, in about the same locations. The difference is that a dryer cord has two straight prongs and two bent ones. A range cord has three straight prongs and one bent one. Make sure that your new cord will fit into the receptacle before installing it (do not plug into a "hot" receptacle; just hold it up next to the receptacle and verify the prongs will fit).
Push the new cable through the connector. If there is no connector one should be purchased; the most common type is a 1" romex connector that has a clamp on one side with 2 screws to tighten the clamp and a large nut on the other. Remove the nut, place the threaded portion through the wall of the dryer and replace the nut.
With the cable through the connector, it is time to terminate the wires on the screws where the old wire came out. Black and Red terminals will take the outside wires on the flat cable (or the same colors), the white wire (center wire on the cable) will attach to the center screw.
The green wire will attach to the spot where the strap was removed from the frame of the dryer in the earlier step. It does not go on the terminal board where the white wire is, but to the frame. It is a grounding wire put there for safety and is not used to supply electricity to the dryer. See the pictures for one location for the green wire; your dryer will likely be different, but in all cases it is to be terminated on the frame or body of the dryer and not on one of the three screws on the terminal board.
Re-attach the cover plate over the wire terminations. It is a wise precaution to turn off the breaker before plugging the dryer in, just in case something is wired wrong. With the breaker off, plug in the dryer and turn the breaker back on.
If the breaker immediately trips, you have put a wire in the wrong place; turn the breaker back off and re-check all the connections. If it doesn't trip, turn the dryer on and make sure it operates correctly.
Congratulations: you have successfully changed out the old 3 prong cord for a new 4 prong dryer cord that will work in your new home, and it wasn't so hard, was it? Ready to tackle putting in a new light fixture now? Or replacing an old plugin that won't hold a cord in any more? These, too, are easy tasks that almost anyone can do - if it is on your "to do" list instructions are available through the links given.
Installing the 4 Prong Cord and Plug
© 2011 Dan Harmon
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