I want to replace just the 3 wire receptacle head of my clothes dryer. there are three wires in the cord. white, black, green. i unscrewed the head and I dont know where which wire goes.

Unplug the dryer then remove the terminal block cover and disconnect the 3-prong cord from the dryer. Note that the cord has red , black, and white wires but sometimes the red and black wires are both replaced by same color wire, usually gray and can switch places. There's also a ground strap wire also connected to the center terminal together with the white (neutral) wire.

Get yourself a 4-prong cord and note that it has red, black, white, and green/yellow wires but sometimes, like the 3-pronged one, the red and black wires are both replaced by same color wire, usually gray and can also switch places. All you have to do now is connect the 3 wires in the same manner they are connected as 3-prong cord to the terminal block. The ground strap wire now just need to be connected to the remaining 4th wire, the green/yellow wire instead of the center terminal together with the white (neutral) wire. Reinstall the terminal block cover and it's done.

It can be observed that converting a 3-prong cord to 4-prong cord is merely splitting the neutral line and the ground thereby increasing the number of prongs from 3 to 4 whereas, on the other hand, converting a 4-prong cord to 3-prong cord is merely joining the neutral line (white) and the ground (green/yellow) thereby reducing the number of prongs from 4 to 3.. The links below might enlighten you further on this matter.

Four-prong to Three-prong Electric Dryer Conversion
Three-prong to Four-prong Electric Dryer Conversion

It's either you convert the 3-prong outlet to 4-prong or the 4-prong cord to 3-prong. But the latter is easier and more feasible. Unplug the dryer then disconnect the 4-prong cord from the dryer. Note that it has red, black, white, and green/yellow wires but sometimes the red and black wires are both replaced by same color wire, usually gray. The red and black wires are lines L1 and L2 reversibly, meaning they can switch places, while the white and green/yellow wires are the neutral line and ground, respectively.

Get yourself a 3-prong cord and note that it has red , black, and white wires but sometimes, like the 4-pronged one, the red and black wires are both replaced by same color wire, usually gray and can also switch places. All you have to do now is connect these 3 wires in the same manner they are connected as 4-prong cord to the terminal block. The wire strapped to the dryer cabinet and connected to the green/yellow wire of the 4-prong cord wire is now left hanging. The last step is to connect this hanging strap wire to the same terminal on the terminal block (center) where the white wire (neutral) is connected and it's done.

It can be observed that converting a 4-prong cord to 3-prong cord is merely joining the neutral line (white) and the ground (green/yellow) thereby reducing the number of prongs from 4 to 3. On the other hand, converting a 3-prong cord to 4-prong cord is merely splitting the neutral line and the ground thereby increasing the number of prongs from 3 to 4. The link below might enlighten you further on this matter.

Electric Dryer Prong Conversion

Hi,
Here is a tip that will help you with changing your dryer plug. Dryer Cord and Wiring Dryer 3 Wire or 4 Wire



heatman101

You have to replace the dryer's 3-prong cord to 4-prong. Get yourself a 4-prong cord then on the terminal block at the rear of the dryer, connect the wires of the 4-prong cord to where the same wire colors (red, black, and white) of the 3-prong cord connects to. The only modification needs to be done is on the green/yellow stripe wire that connects from the white wire terminal to the dryer's cabinet. Remove this wire (green/yellow stripe) from the white wire terminal then connect it to the same wire color (green/yellow stripe) of the 4-prong cord and you are done. The new wire configuration would then be red, black, and white on the terminal block and green/yellow stripe wire on the cabinet.

Hi,
Here is a tip that will help you with changing your dryer plug. Dryer Cord and Wiring Dryer 3 Wire or 4 Wire



heatman101

As I understand you, you have a 4-wire receptacle in the wall and have just acquired a used dryer, that has an older, 3-wire cord attached. You need to change the dryer cord to connect to the existing 4-wire receptacle in the wall. (Dryers sold new, retail do not come with a cord attached so I assume that this must be a used dryer with an existing cord).

If this dryer has a 3-wire cord attached, it MUST be replaced with a newer 4-wire cord, per the National Electrical Code, as you have a 4-wire receptacle. (However I see no reason that you could not use your existing 4-wire cord from your soon-to-be-replaced dryer, if it's still in good shape).

In older dryers, wired with an existing 3-wire cord, there is usually a metal link provided between the center lug (the neutral lug) and a ground connection on the metal chassis. If it's present, this link MUST BE REMOVED WHEN CONNECTING A 4-WIRE CORD. This is very, very, very important.
The reason is, under a fault condition, current could be carried by the neutral conductor (in a 220-volt circuit, the white wire carries the neutral or unbalanced current. There is no neutral in a 120-volt circuit, even though some people think there is).
The presence of this current can be shunted onto the metal frame of the dryer, making it hot to earth ground (until the circuit breaker pops) and providing a possible shock hazard to a person touching the dryer). Removing this link, removes this potential hazard.

When wiring a 4-wire cord, the white wire in connected to the center lug, the two black conductors (could be a black and a red) are connected to either of the lugs on either side of the center lug, and the green conductor is connected to the metal cabinet. (Once you have the metal junction box cover removed from the dryer, you will see a screw driven into the metal cabinet provided to connect the green wire).

Again, when using a 4-wire cord, there must be no connection between the metal cabinet and the neutral connection through the use of a metal link. It must be removed and discarded.

The supply cord on a dryer can be 3 wire or 4 wire, depending on the existing receptacle. All new construction must have 4 wire receptacles for dryer hook ups.
At the back of the dryer you will see a set of three terminals. The outside terminals are for connecting the outside wires of the cord. In a 4wire hook up, the center terminal is for the center, insulated, white wire, the neutral. The bare copper or green wire of the 4wire cord gets connected above these terminals to a lug or stud on the body of the dryer. There may be a strap there. For a 4wire cord connection this strap is connected to the stud only.
The change for a 3wire connection is that the center green wire of the 3wire cord connects to the center of the three power terminals along with the grounding strap from the dryer body above.

Hello wgirdler,
While it is preferred to upgrade the receptacle to a 4-prong type (which includes Neutral & Ground) Code requirements grandfather in 3-prong receptacles in older homes. So if your preference is to remove and replace the power cord on your dryer, make sure you get one that is designed for a dryer application and is 10/3 type. ( 10 Gauge wire with 3 conductors)...
Unplug the original 4 prong plug from the receptacle and pull the dryer away from the wall to gain access to the back of it.
Next, loosen the cord clamp that allows the cord to pass thru the back panel and into the druer compartment.
Open the access cover to where the end of that cord is terminated on a terminal block of the dryer.
Note which color is attached to which terminal ( red to red,black to black, white to white and green to green)...
3 Prong cables do not use a ground wire ( green) in the cord so you would wire the red to red, black to black and white to white ( The red and black are the power conductors and the white ..which is normally terminated between them.. is in the middle. You can get a seperate insulated conductor wire and route it from the ground stud of the dryer to the receptacle metal casing but do this with power disabled at the circuit breaker box...
Hope this helps.
Regards,
Rick

In a three wire system you have 2 hot wires (black and red) and a neutral (white). the ground is connected to the neutral at the dryer. In a 4 wire system you have the 2 hot wires, neutral, and a ground. (green). The ground is connected with the neutral at the circuit panel. The hot wires at the dryer should be on the outside scres, the neutral should be in the center and the ground should be under the green screw. *****. .

Newer electrical codes call for a 4 wire receptacle. never splice appliance cords, it isn't woth the safety issue and they are not very expensive. you need to access the terminal block, which is where the cord goes into the dryer. the cord you use (3 or 4 wire) will depend on what is on your wall. if you wall has a 3 wire plug then you will need to connect the green wire from the center terminal to the frame of the dryer. there is probably a hole and screw next to terminal block. that is where the green wire goes on a 3 wire hook-up. if you have a 4 wire receptacle then the green wire should be hooked to center terminal (white). you will have to obtain the proper cord (pigtail) from a parts supplier.
J