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Plug/receptacle set for 3HP single phase compressor?

Burgerkong

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Attached the coverplate, it's a true 3HP motor with a running amperage (I believe) of 14.5A. Can I use a 20A L14-20P NEMA, or is that undersized because of the 3HP rating, meaning I will have to go up to a 1450 or similar?
 

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wyliesdiesels

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First, u need a 6-20P and r which is 2 hots and EGC/ground. A 14-20p and r has 2 hots, neutral and EGC. A 240v motor doesnt use or need a neutral.

Second, for motor circuits, u need to make sure the outlet and plug are rated for the same or better horsepower rating of the motor.

Technically, to be code compliant u need either #12 THHN or #10 NM-b and 6-30....
 
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Burgerkong

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First, u need a 6-20P and r which is 2 hots and EGC/ground. A 14-20p and r has 2 hots, neutral and EGC. A 240v motor doesnt use or need a neutral.

Second, for motor circuits, u need to make sure the outlet and plug are rated for the same or better horsepower rating of the motor.

Technically, to be code compliant u need either #12 THHN or #10 NM-b

Yeah, I already have a 1420, and was just going to not connect one of the legs, because that's how my electrician wired it. It's all 10 gauge wiring already, but with a 20A breaker I believe, will check.
 

theoldwizard1

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First, u need a 6-20P and 6-20R which is 2 hots and EGC/ground.
If you want locking add an "L" in front. L6-20P and L6-20R. I don't think "locking" is a code requirement. Upgrading everything (building wire, breaker, receptacle and plug) to 30A, L6-30P and L6-30R, is not a bad idea.
 
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theoldwizard1

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Yeah, I already have a 1420, and was just going to not connect one of the legs, because that's how my electrician wired it. It's all 10 gauge wiring already, but with a 20A breaker I believe, will check.

Whaaaa ?

You need both legs ("hots", usually back and red) ! You do NOT need neutral (typically white). Ground is GREEN or bare.

It is is 10 gauge, put a 30A breaker in the box and install a 6-30 or L6-30 unless you are trying to reuse the L14-20.
 
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Burgerkong

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If you want locking add an "L" in front. L6-20P and L6-20R. I don't think "locking" is a code requirement. Upgrading everything (building wire, breaker, receptacle and plug) to 30A, L6-30P and L6-30R, is not a bad idea.

6-30's are only rated to 2HP, I'd need 6-50, or up the voltage.

Whaaaa ?

You need both legs ("hots", usually back and red) ! You do NOT need neutral (typically white). Ground is white or bare.

It is is 10 gauge, put a 30A breaker in the box and install a 6-30 or L6-30 unless you are trying to reuse the L14-20.

Oops, I mean not connect the neutral, slip of the tongue (finger).
 

wyliesdiesels

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Whaaaa ?

You need both legs ("hots", usually back and red) ! You do NOT need neutral (typically white). Ground is white or bare.

It is is 10 gauge, put a 30A breaker in the box and install a 6-30 or L6-30 unless you are trying to reuse the L14-20.

Ground should NEVER be white. Ground is either green or bare.

6-30's are only rated to 2HP, I'd need 6-50, or up the voltage.

Oops, I mean not connect the neutral, slip of the tongue (finger).

There is 3HP rated 6-30 outlets. Ive used them before....
 
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