Dryer: 3 prong to 4 prong plug conversion

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Old 04-03-11, 01:39 PM
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Dryer: 3 prong to 4 prong plug conversion

I have done a bunch of research and I think I have it correct but I just want to double check.

My current dryer has a 3 prong plug, the plug is wired to the dryer with red, white and black wires. My dryer does NOT have a grounding strap connecting the middle (white) terminal to the frame of the dryer. I do have a green wire that emerges from the inside of the dryer (not from the chord) and is attached to the frame of the dryer at the green grounding screw. My understanding is that this wire serves the same purpose as a grounding strap and is at some point connected to the neutral (white) terminal inside the dryer. Would make a bit more sense if that wire was white like I have seen in some pictures but that's a different post.

If I were to follow most of the directions I can find for converting from a 3 to a 4 prong plug I would remove the old plug (red, white and black) and replace with the red, white and black of the new 4 prong plug. I would then attach the original green wire that comes from inside the dryer to the white terminal as well (rather than just leaving it hanging). And finally I would attach the new green wire (from the new 4 prong plug) to the ground screw on the frame where the original green wire had been. Done.

Does this make sense? Thank you in advance for your help.
 
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Old 04-03-11, 02:03 PM
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Does the wire coming out of the wall from the house wiring have a green or bare conductor in it?
 
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Old 04-03-11, 02:32 PM
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There are no wires coming out of the wall. I am only taling about the dryer and the 4 prong plug. I plan to plug this into the 4 prong outlet on the wall but there are no wire coming out of the wall.
 
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Old 04-03-11, 03:04 PM
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The idea of a 4 prong plug and 4 wire cord is to keep the green grounding conductor and white neutral conductor separate. For this to work, the receptacle must also have 4 wires including the grounding conductor. All wires are separate.
 
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Old 04-03-11, 03:33 PM
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There appears to be some confusion when I say plug I mean the plug that is attached to the dryer. I am not working with the outlet in the wall at all. I found this schematic online maybe it will help. It represents what the end result of installation of the 4 prong plug looks like on my system. Notice that the neutral terminal has both the white wire from the new plug and the lighter green wire, which in the picture is called a ground strap.

American A/C & Appliance
 

Last edited by Yurtle069; 04-03-11 at 03:50 PM.
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Old 04-03-11, 05:03 PM
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Unless the receptacle for the plug has 4 wires you need to keep the 3 wire cord. How many prongs will the receptacle accept?

Those pics in the link do not appear to be correct. The connector for the cord is also missing.
 
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Old 04-03-11, 05:36 PM
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Originally Posted by pcboss View Post
Unless the receptacle for the plug has 4 wires you need to keep the 3 wire cord. How many prongs will the receptacle accept?

Those pics in the link do not appear to be correct. The connector for the cord is also missing.
He already says there is a 4 prong receptacle:

Originally Posted by Yurtle069 View Post
There are no wires coming out of the wall. I am only taling about the dryer and the 4 prong plug. I plan to plug this into the 4 prong outlet on the wall but there are no wire coming out of the wall.
It sounds like he acquired a used dryer that came with a 3 prong cord, and needs to change it to 4 prong to match his receptacle.

I just reread the OP and am amending my answer.. It seems the green wire is connected to the neutral inside the dryer. This appears to be the new way they are doing the 'ground strap'. If this is the case, then yes, you will connect the internal green to the neutral stud for 'storage'. BUT, you must test to make sure this is the case before installing the new pigtail. Use a meter set on continuity to make sure the green from inside and the center stud are connected internally. If there is NO continuity, you must leave the green connected to the frame.

Either way, the green from the pigtail must NOT connect to the neutral, it must only connect to the frame.
 
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Old 04-03-11, 06:27 PM
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Those pics in the link do not appear to be correct
I was ready to agree with pcboss on this till I found a Whirlpool pdf showing the same thing. Whirlpool calls the green wire from internal in the dryer a neutral ground wire and I believe it's misleading. It appears to me that this green neutral ground wire is attached to only the neutral internal to the machine and when attached to the frame allows the machine to be grounded through the neutral of a 3-wire dryer circuit (Like JerseyMatt also said). That being said, in a 4-wire connection, the green wire is attached to the neutral screw on the terminal block. In my opinion, this is misleading because it isn't a ground wire in this application because it only connects to the neutral. This connection isn't even necessary.

Look at steps 3-6 on pages 7 & 8
http://www.whirlpool.com/assets/pdfs...ruction_EN.pdf
 
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Old 04-03-11, 10:41 PM
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Hence my confusion, thanks for that manual Joe. Based on the manual the green (neutral ground) wire originating from the dryer itself is actually connected to the neutral terminal somewhere inside the appliance and therefore serving the same function essentially as a "ground strap" connected directly to the frame from the neutral terminal. My particular dryer also happens to be a whirlpool, so I think I might be ok but I will borrow a meter from the electronics shop at work and check to see if the neutral ground and neutral terminal are indeed connected like you said Matt. Thank again guys for your help. I will post the results of the meter test when I get them.
 
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Old 04-07-11, 07:14 PM
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I checked the continuity between the white terminal and the "neutral ground" (green wire originating from the dryer) and it showed continuity. I think that this confirms the previous post including the link to the manual for the whirlpool dryer. I therefore connected the neutral ground to the neutral terminal and everything seems to work fine. Thank you to all of you for your help.

Jason
 
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Old 04-08-11, 08:19 AM
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I remember being confused by that manual at one point too. It seems that the translated Engrish "neutral ground" as a verb instead of a noun. As in: "this is the wire that grounds the neutral".
 
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