3 Wire or 4 Wire cord for Dryer?


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Old 09-24-06, 07:59 AM
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3 Wire or 4 Wire cord for Dryer?

I have an electrical dyer from the previous house. It has 4 wires. But the current house wall outlet has only 3 wire, that kind specially designed for dryer with 30amp.

Should I change the recapticle or the wire? I did buy a 3 wire cord. But when I opened the connection box on the dryer, I found it has 2 hot wires, called L1 and L2 with different colors.

I am afraid I have to change the recapticle.
Thank you in advance.
 
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Old 09-24-06, 08:24 AM
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You match the dryer to the receptacle, not the other way around.
 
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Old 09-24-06, 08:36 AM
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Originally Posted by lzhang
I have an electrical dyer from the previous house. It has 4 wires. But the current house wall outlet has only 3 wire, that kind specially designed for dryer with 30amp.

Should I change the recapticle or the wire? I did buy a 3 wire cord. But when I opened the connection box on the dryer, I found it has 2 hot wires, called L1 and L2 with different colors.

I am afraid I have to change the recapticle.
Thank you in advance.
Most existing 3 wire dryer circuits are acceptable if they were compliant with the electrical code when installed. That is how (most) residential dryers were installed in the not too distant past.
You can (most likely) change the cord on the dryer to a 3 prong and still be legal (code wise). Your existing 4 wire hook-up on your dryer will have the neutral (white) and ground (green) on seperate connections on the dryer. You will attach these (white and green) to the same terminal and (bond) to the metal dryer housing. The dryer will then use the neutral to both provide a (120V) return circuit conductor to the breaker panel and also ground the metal dryer housing through the same wire.
The (2) hot conductors will hook up to the same place that they are now on the dryer.
The wiring from the breaker panel is usually #10 copper protected by a 30 amp breaker on clothes dryers..
Is this what you have? You should check.
Edit to add: The L1 and L2 connections on the dryer are where the (2) hot wires on the cord connect. The third wire on the cord is the ground. On most (gray) flat dryer cords (3 wire) the ground conductor is in the center of the cord.
Check the receptacle to make sure it's wired correctly. Two hot wire slots and a ground slot where the cord plugs in that match the cord configuration.
Use this information at your own risk. You are responsible for the safety of the installation and of anyone involved with it. I won't be held responsible for any accidents or injury.
steve
 

Last edited by hillbilly ace; 09-24-06 at 08:58 AM.
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Old 09-24-06, 09:20 AM
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Of course there are two hot wires.That's how 240 volts is supplied in the US.

Leave the receptacle alone and buy a new cord for the dryer.

OR

Change the circuit to be a four wire circuit and a four wire receptacle. This may or may not be difficult, depending on where the receptacle is located with respect to the panel..
 
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Old 09-24-06, 09:21 AM
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Actually the middle conductor on a 3-wire dryer cord is the neutral, not the ground. In older 3-wire dryer and range circuits the ground was allowed to be bonded to the neutral.

To go from 4-wire to 3-wire you connect the two hots the same as before.
The center conductor on the cord goes to the center post of the terminal block. CONFIRM this is the white.
You now need to bond the ground to the neutral. Hopefully whoever installed the 4-wire cord simply folded the bond strip away and left it there. You need to connect the dryer ground to the white (neutral) post on the terminal block.

This web page will help. You'll need to copy and paste:
http://www.selfhelpandmore.com/switchoutlet/dryer/dryershowall.htm
 
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Old 09-24-06, 11:05 AM
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Originally Posted by Speedy Petey
Actually the middle conductor on a 3-wire dryer cord is the neutral, not the ground. In older 3-wire dryer and range circuits the ground was allowed to be bonded to the neutral.

To go from 4-wire to 3-wire you connect the two hots the same as before.
The center conductor on the cord goes to the center post of the terminal block. CONFIRM this is the white.
You now need to bond the ground to the neutral. Hopefully whoever installed the 4-wire cord simply folded the bond strip away and left it there. You need to connect the dryer ground to the white (neutral) post on the terminal block.

This web page will help. You'll need to copy and paste:
http://www.selfhelpandmore.com/switchoutlet/dryer/dryershowall.htm
Thank you all.

I already bought the 3 wire cord. So the middle one goes to the Neutral (white). Speedy, I like your link. It says.

"Since in this case the neutral serves as a neutral and a ground connection, a jumper band (ground strap) is also connected to the center terminal and to the frame of the dryer. A green wire could also be used to connect the center connector to the frame of the dryer."

I am going to buy a length of thick wire (10) to do the ground strap.
 
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Old 09-24-06, 07:55 PM
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I did it exactily as you said. I do not have clothes to test yet.
When I open the door, the light is on. I believe it will work.
I will keep you posted. Thanks again!
 
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Old 09-25-06, 04:40 AM
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Cool

[QUOTE=Speedy Petey]Actually the middle conductor on a 3-wire dryer cord is the neutral, not the ground.

No, actually it's the grounded conductor.
The green one is the grounding conductor.
There is no neutral in this circuit.
steve
 
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Old 09-25-06, 09:01 AM
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Actually Steve this does fit the definination of a Neutral. Most of the times we use that word it is not correct, but this time it is.

But, we should not confuse everyone by arguing that point. It is pretty much industry standard to say Neutral weather the wire actually is serving as a neutral or just a grounded conductor. (every neutral is a grounded conductor, it is requred by code. Not every grounded conductor is a neutral.)
 
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Old 09-25-06, 02:07 PM
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Yes Steve, in this case it IS the grounded conductor (proper term). "Neutral" to all lay people and most electricians.

NO, it is NOT the grounding conductor.

YES, this circuit DOES most definitely have a neutral.
ALL typical electric dryers have neutrals. Older circuits did not have a dedicated ground.
 
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Old 09-26-06, 04:43 AM
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I am closing this thread as the question has been answered.
 
 

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