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Help! Going from a 4 prong plug to a 3 prong plug??? What do I do with the White

Help! Going from a 4 prong plug to a 3 prong plug??? What do I do with the White

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  #1  
Old 04-09-15, 07:34 PM
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Help! Going from a 4 prong plug to a 3 prong plug??? What do I do with the White

I am making an extension cord that plugs into my dryer outlet. My dryer outlet is a 4 prong (Black, Red, White, Bare). Name:  20150409_211737.jpg
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But the plug that I am using the extension cord for is a 3 prong. I know that Black and Red are Hot.Name:  20150409_211818.jpg
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My Question is: Do I tie the white (neutral) in with the ground (Bare) or cap it off?? I have been told to cap the white wire, then another electrician said to tie the white and bare in the ground together.

What do I do? I don't want to fry the expensive 10g wire that I made the extension cord with.
 
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  #2  
Old 04-09-15, 08:03 PM
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That appears to be cable not cord. The dead give-away is the bare ground. Cable can't be used as a cord. If the cord is for 240 volt only you would use 3 conductor service cable (white, black, green). Example: http://www.lowes.com/ProductDisplay?...llow&cId=PDIO1

NM-b cable is only to be used as building wiring.
 

Last edited by ray2047; 04-09-15 at 08:22 PM.
  #3  
Old 04-09-15, 08:37 PM
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What is the purpose of the extension cord?
 
  #4  
Old 04-09-15, 08:42 PM
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Yes I used cable and wired both ends. But is the white and bare to be connected together and then to the ground on the plug? Or do I just eliminate the white wire?

That is all I am asking. I made the cord and yes it can be used. Just a simple question on what I do with the white wire.
 
  #5  
Old 04-09-15, 08:46 PM
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It is for a welder that is a 50amp or 30amp, but has a 50Amp plug.
 
  #6  
Old 04-09-15, 09:19 PM
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Cable is not intended for that purpose. It is a code violation. Even if it was you should have used 10-2 not 10-3, double mistake. The welder is 240. You do not use a neutral on 240. That would be the white. What you are doing is wrong but if you don't care that it is wrong cut off the white on both ends.
 

Last edited by ray2047; 04-09-15 at 09:40 PM.
  #7  
Old 04-09-15, 09:43 PM
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So I eliminate the white on both ends? Will it still trip the breaker if it gets overload? I know it is not code, but my main concern is a fire. That is why I have an extension cord.
 
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Old 04-09-15, 10:29 PM
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Will it still trip the breaker if it gets overload?
Yes. The current flow across the breaker is on the two legs of the 240. Of course if that welder is 50 amp the 30 amp breaker may trip if it doesn't have a low percentage duty cycle.
my main concern is a fire. That is why I have an extension cord.
An extension cord does not reduce the risk of fire but could slightly increase the chance of fire. How long is the extension cord? Why aren't you installing a receptacle for the welder?
 
  #9  
Old 04-10-15, 04:59 AM
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Gotta love folks who are certain of what they intend to do despite its illegality and all warnings and advice from experts. Why bother asking in the first place??
 
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