40 amp to 20 - 220 240v


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Old 02-16-13, 02:26 PM
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40 amp to 20 - 220 240v

I have an outlet connected to a 40A breaker for a welder. I want to change it with a new pin pattern to accept a compressor that is rated 20A. The matching outlet for the compressor is rated as "20 Amp max". Do I have to change the breaker, and if so, how?
Thanks
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Old 02-16-13, 02:48 PM
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Welcome to the forums! Your 40 amp receptacle will need to be changed to a 20 amp receptacle. Your 40 amp breaker, will also need to be changed to a 20 amp breaker. Wiring will not be a problem, since you are downsizing, HOWEVER, you may not be able to fit the wire under the clamps of the 20 amp receptacle. This may force you to rewire it with 10 gauge wiring.

I would leave the welder set up and run new wiring with a new breaker and receptacle to a convenient location. What size wiring do you have at the welder, now?
 
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Old 02-16-13, 04:28 PM
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thanx

I don't intend to use the welder. Thoughts?
 
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Old 02-16-13, 04:51 PM
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You can still use the existing wire.

If it's too big to fit in breaker add two small # 12 tails to the wires with wire nuts.
 
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Old 02-17-13, 06:42 AM
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Will take a look at the wire size. Your idea about another breaker makes sense. Will be in touch. Thanks!
 
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Old 02-17-13, 07:01 AM
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You could install a subpanel near the welder receptacle. Then keep the 40 amp welder receptacle and add one or two 20 amp receptacles using breakers in the subpanel.
 
 

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