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Odd question about hard wiring an air compressor

Gore

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I plan on purchasing the 60gal. Kobalt compressor from Lowes tonight and I am trying to get all of my ducks-in-a-row for the wiring portion. I have seen many people post that they(Kobalt/Lowes) recommend the compressor to be hard-wired so that's what I'm going to do. I could put a plug in later if I want to, plus my breaker is 15' from the compressor so I should be fine as per code(please correct me if I'm wrong).

My question is how do people suggest routing the wire for a hard-wired set-up? I would like to keep it as clean as possible and run the wires through the wall, but how do you run the wire from the wall to the compressor? Does it just come out of a hole in the wall(with maybe a decorative faceplate)? Is there some type of requirement for conduit for the wire...or is the wire just exposed romex with a clamp going into the compressor? The idea of running a wire straight out of the wall just sounds ghetto.
 
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pattenp

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Since you don't need a disconnect at the compressor because it's only 15 ft from the breaker you can use a 4X4 junction box in the wall and use a face plate with a knockout and go from there with flex conduit to the compressor.
 

tonycastec

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Wouldn't it be more flexible if you used a 10-50 or 14-50 plug and receptacle?It also is a convenient physical disconnect to use if you need to work on the compressor.
 
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Gore

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Wouldn't it be more flexible if you used a 10-50 or 14-50 plug and receptacle?It also is a convenient physical disconnect to use if you need to work on the compressor.

I completely agree that having a plug would be ideal for moving the compressor, for whatever reason, or in case I wanted to plug a welder in. The problem I see is two-fold...1) adding a plug adds additional cost (not more than say $50 I know)...2) I have seen posts indicating that not hard wiring the compressor can void your warranty (which sounds shady but it is what it is).

With hard wiring I can always switch to a plug down the road but it wouldn't be so easy to do the reverse.
 
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Gore

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flex conduit, with proper connectors.

Outside of the wall from the box to the compressor, or from the wall to the compressor? My box is recessed so if I run it on the outside of the wall I would still have the same issue of making it look clean.
 

ishiboo

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Oct 27, 2010
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Oshkosh, WI
I plan on purchasing the 60gal. Kobalt compressor from Lowes tonight and I am trying to get all of my ducks-in-a-row for the wiring portion. I have seen many people post that they(Kobalt/Lowes) recommend the compressor to be hard-wired so that's what I'm going to do. I could put a plug in later if I want to, plus my breaker is 15' from the compressor so I should be fine as per code(please correct me if I'm wrong).

My question is how do people suggest routing the wire for a hard-wired set-up? I would like to keep it as clean as possible and run the wires through the wall, but how do you run the wire from the wall to the compressor? Does it just come out of a hole in the wall(with maybe a decorative faceplate)? Is there some type of requirement for conduit for the wire...or is the wire just exposed romex with a clamp going into the compressor? The idea of running a wire straight out of the wall just sounds ghetto.

I would do a receptacle and not worry about "voiding warranty" as you could just cut it off and pretend it was hard-wired. BUT.

I would surface-mount a 4x4 box on the wall, and use a bottom knockout to drop to flex. Flat cover plate.

You could also recess a 4x4 box, and use a 4x4 cover with a single knockout in the middle, but I think it looks cleaner dropping out of the bottom versus coming straight out the front. :)
 

ishiboo

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Outside of the wall from the box to the compressor, or from the wall to the compressor? My box is recessed so if I run it on the outside of the wall I would still have the same issue of making it look clean.

Wait. What type/size of box is already in the wall?
 
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Charles (in GA)

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50 mi south of Atlanta
By code, you would need to use a receptacle and plug that are sized to the wire and circuit breaker you are using, for example, a 30 amp receptacle and plug, 10 gauge wire, and a 30 amp breaker. Problem is, its quite possible the plug and receptacle, while capable of the amperage, are not MOTOR RATED for a high enough horsepower to handle the compressor. This is due to large inrush current of motors when they start, so the OP needs to determine if the receptacles and plugs are properly motor rated. This is a good reason to hardwire the compressor, especially if it is a stationary unit anyhow.

Charles
 
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Gore

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If I decide to add a receptacle down the road I would use a 30a twist lock receptacle...I plan on running 10/2 and a 30a as it stands now. I have seen that people are getting away with 12/2 as the Kobalt pulls 18a(ish) but I would rather play it safe if I ever upgrade.
 

Falcon67

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Merkel, TX
This is how my 240V 60 gallon was wired in the old shop, 16' from the panel. A piece of 12-2 cord is all it takes. If you insist on it being in the wall, then place an old work box in there and put a metal cover with a knock out on the box. Wire your compressor whip into the box with an appropriate clamp.
AirSystem_A.jpg
 
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Gore

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Is the 4x4 code or just because of the heavy duty nature of 10/2 and making easy to work with? Would a standard old-work double gang box be sufficient?
 
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