Appliance question / elect dryer or stove

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  #1  
Old 05-24-20, 08:56 PM
R
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Question Appliance question / elect dryer or stove

Today they want you to used 3 conduct with ground .So the neutral and ground are separate at the dryer. On the older cable they used 3 conductor on the dryer the dryer you two hots give you 220 the middle wire was the neutral\ ground because they where bonded at the appliance . My question is that on the 3 conductor and the middle wire be bonded with the dryer. How they get 110 ? If they used that middle wire to get 110 ,would that make the dryer out side hot say you touch the dryer and say a water line .Isn't the controls say 110 and the heating element used 220.
 
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Old 05-24-20, 09:17 PM
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It would only be hot if the neutral/ground become disconnected. Although a low possibility, it could happen. That is why new installs require a four wire feed.
 
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Old 05-25-20, 03:14 AM
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Yes they use the third wire to get 110.
L1 (line 1) to Neutral/ground = 110 volts
L2 to Neutral/ground = 110 volts
L1 to L2 = 220 volts.

Two things would have to happen at the same time for the units frame/case to become live.
First one side of the 220 would have to short to the frame.
Second the Neutral/ground wire would have to disconnect.

If the Neutral/ground stayed connected then the breaker would trip as soon as either side of the line shorted to the frame.

I do not know how often this happened in the past that they went to a 4 wire hookup.
Seems very unlikely to me so it may just be as an extra protection.

 
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Old 05-25-20, 06:14 AM
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I can remember touching a appliance and getting a small shock. It happened enough that the code changed.
 
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Old 05-25-20, 10:57 AM
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Today they want you to used 3 conduct with ground .
That was a code change 24 years ago!
 
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Old 05-25-20, 11:14 AM
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Two things would have to happen at the same time for the units frame/case to become live.
First one side of the 220 would have to short to the frame.
Second the Neutral/ground wire would have to disconnect.
Technically incorrect.

As soon as the neutral (3rd) wire was opened....... there would be hazardous voltages on the cabinet.
The motor needs 120v. It would be connected to one leg of power and the cabinet creating a hazard.

Point being..... it doesn't need an actual short..... the motor and the electronics are a short.
 

Last edited by PJmax; 05-25-20 at 11:33 AM.
  #7  
Old 05-26-20, 06:54 AM
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I stand corrected.

I can see how you would get 120 onto the frame.

I do not agree that "the motor and the electronics are a short."
Circuit path yes, a short no.

 
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Old 05-26-20, 12:33 PM
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Yes..... circuit path is definitely a better description.
 
 

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