Air compressor 3 prong to dryer 4 prong

[foxbody306]

Whats up people I recently bought a snap on BRAC560v air compressor(don't bash me) and I wanna hook it up to to my dryer plug. The dryer plug has 4 prongs and 4 wires going to it, the air compressor only has 3 wires. This is the only 240 volt outlet in the house. The compressor is only gonna be 3 feet away from the outlet right next to the dryer and washer machine. My question is would it be alright to hook it up to a 4 prong socket and if so how would I do going about that. The amp ratings are 20 @ 208/230 and is a single phase 5hp engine.

Any help would be great, i'm looking to paint my car and I figured buying a compressor is still cheaper then havng a shop do it plus ill always have the air compressor

 

[pattenp]

You can by using a 4 prong plug on the compressor without using the neutral. That being said, it does not meet NEC requirement nor UL listings since NENA plugs are rated only to 3HP. Plus the compressor most likely requires hard wiring.

If you are determined to use a cord and plug use 10/3 sjoow or soow cord. I assume the dryer outlet is 30 amps.

 

[foxbody306]

I just looked inside the breaker box and the dryer runs off of 2 30 amp breakers, now do you think this will be safe? The compressor isn't gonna be running all the time maybe once or twice a week and not for longer then 10 minutes at a time. Also what would happen if I didnt run the neutral wire because I cant use it?

Worse comes to worse it will just pop the breaker right?

 

[pattenp]

I'm just talking from my point of view. Is it safe, yes. If it pops the 30A breaker then you know you need a larger circuit, no harm done. But I wouldn't keep using it on that circuit if the compressor on a regular basis pops the breaker. As far as the neutral goes, the compressor doesn't use it so it's not needed. All the compressor needs are the 2 hots for 240V and the equipment ground.

Edit: To be clear, 10/3 cord is 3 conductors. It's not numbered the same as building wire such as Romex, where 10/2 is 3 conductors.

Edit Edit: I'm such a code Nazi I can't believe I just said this. On another post I was saying the compressor should be hardwired, no ifs, ands or buts about it.

 

[Aceman]

Edit Edit: I'm such a code Nazi I can't believe I just said this. On another post I was saying the compressor should be hardwired, no ifs, ands or buts about it.

It's hard to do when most folks on here only want to buy the equipment but don't want to take the time or money to wire it right. Fortunately, most of my customers have been with me a long time and they know when they buy something new, sometimes it costs just as much to run wire to it as it did to buy the piece of equipment.

 

[foxbody306]

Alright, thanks for the info. What I gathered here is the that the black and white wires are for the hot wires(power) and the green wire is the ground. All I have to do is ignore the neutral on the 4 prong socket cause it's not gonna be used.

Just a question though what does the neutral wire do? I know I don't have one but my dryer does and i'm guessing that this is a new code because older dryers use to only have 3 prong sockets compared to todays 4 prong sockets

 

[CNGsaves]

Dude, you just bought $1,735 SnapOn compressor . . .
. . .
. . . . . . but don't have $200 bucks to properly wire it ??

http://buy1.snapon.com/catalog/item.asp?P65=yes&tool=all&item_ID=646010&group_ID=681243

So what is the long-term plan . . . have a 60 gal compressor sitting next to washer & dryer INSIDE the house ???

 

[pattenp]

Alright, thanks for the info. What I gathered here is the that the black and white wires are for the hot wires(power) and the green wire is the ground. All I have to do is ignore the neutral on the 4 prong socket cause it's not gonna be used.

Just a question though what does the neutral wire do? I know I don't have one but my dryer does and i'm guessing that this is a new code because older dryers use to only have 3 prong sockets compared to todays 4 prong sockets

Yes, you leave the neural connection on the plug empty. The neutral provides 120V for controls on the dryer. So between either hot wire and neutral is 120V. Between the two hots is 240V.

Edit: Forgot to say the older 3 prong dryer plug was an ungrounded plug. It had 2 hots and neutral. The neutral was bonded to the frame of the dryer. Now dryer cords have an equipment ground and the neutral is not bonded to the dryer frame.

 

[James-W]

Dude, you just bought $1,735 SnapOn compressor . . .
. . .
. . . . . . but don't have $200 bucks to properly wire it ??

Yeah, that thought went thru my mind too.

 

[foxbody306]

I knew I was gonna hear someone say something about that, only reason I got it was cause I could finance it. I'm only 19 years old and hard headed, i didn't feel like saving up for one and no one would help me with a sears or home depot card. After spending 1900 on the compressor its still cheaper then having someone else paint it even if it leaves me scrounging for some money at times.

Do i have 200 bucks for someone to wire it in yes, do i wanna give someone 200 dollars for something i think i can do myself no

Like i said i'm hard headed, but thanks for everyone trying to help out

 

[CNGsaves]

Just giving you a hard time !!

If you'd let GJ know you were looking for 60 gal 5 HP compressor, someone in your area might have found you a quality compressor for under $400 . . . . that would have left you $1500 to do LOTS of other things !!

If ink isn't dry on the "Credit Purchase" from SnapOn for compressor, heck I'd see if I could weasle out of deal . . . . ie turn it back in.

A "SnapOn" compressor is not anything special versus say a Puma or Black Maxx compressor for 1/3 the money.

Update your GJ Profile with City / State and see if any locals can help you out.

 

[foxbody306]

One last question pattenp theres a little green wire that's maybe 16 gauge that bolted to the bottom of the motor plate then to the switch im this is the ground wire. Now for the green thicker wire this is gonna be capped off meaning not used or does this go to one of the prongs on the 4 prong socket

Its a done deal already lol, I know snap on doesn't even make the compressors. Ive had it for about 3 months and its half payed off now

 

[pattenp]

You will be using a 3 wire cord so on the 4 prong plug you'll have the 2 hots (white&black) and a green ground connecting to the plug. The half round prong is the ground. The 2 flat prongs are the 2 Hots, The L shaped prong is the neutral and is not used. The small green wire from the motor base to the switch housing is grounding the compressor body, and motor frame. The green from the cord will connect to a ground screw inside the pressure switch box to the box itself. The two hots go to to the pressure switch.

I assume this is your outlet...

 

[foxbody306]

Thanks man

 

[foxbody306]

.....and yes that's the outlet, the 2 straight ones left and right on the picture is where the black and white wires off the compressor are gonna go to(hot wires) and the green one off the compressor is gonna go to the half circle the top one ground)

 

[Charles (in GA)]

In the four prong plug shown above, the neutral is the L shaped pin. It has a WHITE wire supplying it from the house. The two hots, flat blades left and right are, generally, supplied by the house wiring as RED and BLACK, and the ground is the D shaped pin, with the green wire. Go buy a four wire dryer cord with the longest cord possible at Home Depot or Lowes or elsewhere and wire it to the compressor, tying back the white wire after capping it with a wire nut.

Simply do away with the short piece of wire that is connected to the pressure switch, and connect the dryer cord you bought right to the pressure switch terminals. If you do use the wire connected to the compressor, take a red marker and color the white wire red so someone will know it is not a neutral wire.

Charles

Charles

 

[wyliesdiesels]

Seeing as its a 5HP motor, its possible that u will have nuissance trip issues...

 

[alfredeneuman]

Dude, you just bought $1,735 SnapOn compressor . . .
. . .
. . . . . . but don't have $200 bucks to properly wire it ??

^^^^^^^^^
It seems like this is a common theme. Buy an expensive piece of equipment, and want to hook it up Mickey Mouse style, as cheaply as possible. Code be damned

 

[foxbody306]

It worked! I used it for about a hour and a half without the it tripping the breaker, thanks to everyone that tried to help out. I did wire it in the Mickey mouse way, just cause you like to do things a specific way doesn't mean I'll do the same. Fred just because you like to take it up the rear doesn't mean I'll do the same

Thanks again for everyone that helped

 

[madosta]

I'm not sure how I feel about this thread... lol.

Glad the compressor is wired and working for now and people do this all the time.

Keep on keeping on.

 

[alfredeneuman]

Wow

Good luck and Goodbye......Thanks for keeping it civil!

 

[wyliesdiesels]

Wow

Good luck and Goodbye......Thanks for keeping it civil!

Woa. Thats what u get for giving FREE electrical code advise? Geez...I guess u gotta keep in mind that the OP is 19 and probably stuck in high school attitude mode...

 

[Black_Z28]

Fred just because you like to take it up the rear doesn't mean I'll do the same

Thanks again for everyone that helped

HA, coming from the guy that bought a $1700 compressor; you could have easily spent $500 and still done the exact same thing you're planning to do.

All these guys are doing is try and help you from having possible problems in the future, which likely will end up costing more money then just doing it right in the first place.

 

[C96]

...You’re thanking people for instructions on how to connect your compressor in violation of the NEC…