Queston On 240 Plugs and Receptacles

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  #1  
Old 06-17-13, 02:30 PM
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Queston On 240 Plugs and Receptacles

Mod note: Post separated from http://www.doityourself.com/forum/el...off-stove.html. First part copied back to that post..



  • Eh, bit tangential but, I've got a 220v question

    Say I've got a few 14-30 three prong dryer cords & outlets laying around;

    Is there some specific paragraph of the code book that directly offends the wiring gods
    if I re-use these plugs as 240v grounded plugs for 240v outlet and a 220v motors?
    Basic table saw, compressor, binford-tool-time- daiquiri maker?
 

Last edited by ray2047; 06-17-13 at 03:31 PM.
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Old 06-17-13, 03:29 PM
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Why would you want to use the cumbersome 14-30's on 20 amp circuits? I guess because they are there, huh? I'm using 3 pronged receptacles on all my power tools in the shop, but that's the way the motors are wired..
 
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Old 06-18-13, 05:22 AM
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Sorry, mixed up from editing there.
Upgraded dryer outlets to newer 14-30 four wire plugs and outlets. (House and rentals).
The extra cords and outlets are old fashioned drier plugs, NEMA 10-30 three wire, three prong.

For 240v equipment, modern plug is 6-30, with two hots and ground. Old dryer plug is 10-30 with two hots and neutral.

Does code allow 10-30s to be reuse and rewired as 240v grounded connectors;
or does code require that millions of old cords and outlets get chucked into the landfill?
 

Last edited by Hal_S; 06-18-13 at 05:42 AM.
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Old 06-18-13, 05:39 AM
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Grandfathered only as long as in use for original purpose. The original purpose was never for shop tools. The receptacle does not have a ground. Code says you must follow the manufacturer's recommendation. If the manufacturer says a grounded plug (or connection) then you must use a grounded plug (or connection). The plug isn't grounded and the receptacle isn't grounded. The use of this plug and receptacle was when allowed a very specific exception to the code. Shop tools were never part of that exception.
 
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Old 06-18-13, 05:57 AM
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Grandfathered only as long as in use for original purpose.
Curious now, what's the actual language and code cite for that?

"Original purpose" was a general purpose outlet, providing 240v with grounding through neutral, correct?
 
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Old 06-18-13, 06:02 AM
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It was never designated for use as a 240 volt receptacle. It was designated as a 120/240 receptacle. Your shop tools are not 120/240 in most if not all cases.
 
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Old 06-18-13, 06:11 AM
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It was never designated for use as a 240 volt receptacle. It was designated as a 120/240 receptacle.
Yes, I know it was LATER given the NEMA designation of 10-30,

I'm asking about two things that are rather different,


(1) the code citation on original purpose

and

(2) the original purpose it was DESIGNED for.


The unsolved 120v/204v question from a prior discussion
 

Last edited by Hal_S; 06-18-13 at 06:27 AM.
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Old 06-18-13, 10:10 AM
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The unsolved 120v/204v question from a prior discussion
What is unsolved there ?
 
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Old 06-18-13, 10:15 AM
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Art. 406.10 , (B) , Grounding-Pole Identification, requires Grounding-Type receptacles to have the receptacle Grounding termination to be so "identified".
 
  #10  
Old 06-18-13, 11:19 AM
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Originally Posted by Nashkat1

What is unsolved there ?
The original rationale for connecting a live current carrying wire to the appliance chassis...

I figure that the earliest electric stoves would be pure 240v; the later additions of things like clock, timer and light bulb were overlooked.

But, as noted below, with a dryer there is always a fair sized motor, directly connected to the chassis...
  • Originally Posted by Tolyn Ironhand

    I also find it hard to believe that the Code would ever have allowed bonding the chassis to a neutral wire, with the amount current of a 120 volt drum motor.

    Originally Posted by ray2047

    The reason I have read for allowing bonding chassis to neutral is the copper shortage surrounding WWII but I can't provide a cite either.

    P.S. Gee, where's Furd when you need him?
 
  #12  
Old 06-18-13, 02:16 PM
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The 3-wire connection was permitted in WWII as an effort to save copper. Why they didn't stop permitting it after that, I don't know. Nowadays it just makes a PITA.
 
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