230v 5HP Compressor Plug/Receptacle

[atvkid4eva]

I just purchased a 230V 5hp Champion 80gal compressor. I currently have a 30 amp circuit ran with 10 guage wire. Can you guys recommend with plug/receptical would be best for this application? After some reading on here, some people say it needs to be hardwired due to no plug being rated for 5hp, but if possible i would prefer a plug. Let me know your thoughts. Thanks!

 

[finn]

Hardwire only

 

[jdm5]

Well Properly rated pin and sleeve is fine too, but that will be big $$$. I found a used one on ebay for ~$100 for my install when I needed it.

 

[mudhog]

most RV plugs are 30amp

 

[atvkid4eva]

Well Properly rated pin and sleeve is fine too, but that will be big $$$. I found a used one on ebay for ~$100 for my install when I needed it.

Yeah, I know this is an option as well. Could you give me anymore info on the type that you bought, so I could look into pricing.

 

[SundayFunday]

Here's a 30amp plug from Grainger that should work on your 30Amp circuit.

Not cheap, but there are probably cheaper sources out there. They have the outlets also.

https://www.grainger.com/product/49...kwcid=AL!2966!3!264955915676!!!g!438993006185!

EDIT !!! It was pointed out that although this plug is rated for 30 amps, it is only rated for 3HP.

 

[Chuckster in NJ]

Check out Home Depot for a 250 volt/30 amp twist lock plug and cord cap then attach them to a piece of 10-3 SJO (rubber cord) and you will be good to go....... Very easy job!

BTW! There are plugs and receptacles available at HD for up to 50 amps.

 

[matt_i]

Here's the thing. You can put a plug and receptacle, a L14-30 will do just fine, a 6-50 oven plug even better. It will run until the cows come home with no issues.

But then you don't get to stand under the roofline of the NEC.

The electrical code does have in mind arc-flash (if the plug is unseated with the motor drawing amps) which can damage you, the plug, and the receptacle which is why they spec hardwired for motor loads.

 

[mike93lx]

What is the advantage to a plug on a 5hp stationary compressor? Just trying to understand the goal.

A disconnect is code compliant and much cheaper.

 

[atvkid4eva]

What is the advantage to a plug on a 5hp stationary compressor? Just trying to understand the goal.

A disconnect is code compliant and much cheaper.

I guess you do have a point. The thing is so heavy that i doubt it will ever be moved.

 

[mike93lx]

Is your wire #10 in conduit or romex? If it is romex, 10/2 isn't enough for 5hp. You'll need either 8/2 romex or #10 thhn in conduit

 

[Augus7us]

Is your wire #10 in conduit or romex? If it is romex, 10/2 isn't enough for 5hp. You'll need either 8/2 romex or #10 thhn in conduit

Per the sparkies here this is what I ran also (8/2). That and I thought that was overkill so I looked it up and, of course, the sparkies were correct.

My box is technically not in site of my breaker panel so I just have mine running to a disconnect then to my mag switch on my compressor. 5HP also for the record.

 

[The Tool Tyrant]

I guess you do have a point. The thing is so heavy that i doubt it will ever be moved.

EXACTLY! Hardwire it.

 

[bradleykd]

I run mine on a 30A plug/socket. I am an electrician and understand the code, but I am willing to take to risk. Having an outlet allows you to use that 230V run for something other than the compressor if you have multiple things.

 

[Slowbuilder]

Here's a 30amp plug from Grainger that should work on your 30Amp circuit.

Not cheap, but there are probably cheaper sources out there. They have the outlets also.

https://www.grainger.com/product/49...kwcid=AL!2966!3!264955915676!!!g!438993006185!

The specs on that plug say it is rated for 3hp.

 

[SundayFunday]

The specs on that plug say it is rated for 3hp.

Whoops!! you are right, I just looked for "30 Amp" and didn't read the entire description. Does that mean any more than 3 HP draws more than 30 Amp?

 

[mike93lx]

Whoops!! you are right, I just looked for "30 Amp" and didn't read the entire description. Does that mean any more than 3 HP draws more than 30 Amp?

No, a 5hp draws less than 30a when running.

If you unplug a motor when under load, it creates an arc flash hazard, which is very dangerous. Think super heated sparks. That's why high rated plugs are of a different style, called pin and sleeve where the prongs are shrouded

 

[On-Wheel]

I use 1 outlet for 3 things.Air,welder and heater.

 

[Paul_The_Builder]

If you're looking for a cheap way to have a "service disconnect" you can use a fused disconnect typically used for air conditioner units. They're cheaper than a plug and receptacle.

This one is $17, in stock at Home Depot, and is rated for 10HP.

 

[Marctrees]

Is this "Arc flash" a real thing in the example we are talking about here ?

Please someone explain.

Marc

 

[mike93lx]

Is this "Arc flash" a real thing in the example we are talking about here ?

Please someone explain.

Marc

Google arc flash.

Yes, unplugging a motor under heavy load can cause one.

At high enough current and voltage, it can easily kill or seriously injure someone. Much more of an issue in industrial settings with 460V systems

 

[7635tools]

I run mine on a 30A plug/socket. I am an electrician and understand the code, but I am willing to take to risk. Having an outlet allows you to use that 230V run for something other than the compressor if you have multiple things.

If you’re an electrician, than you should have dedicated 240v outlets for your multiple things. Guys that aren’t in the know will do stuff like that but if you’re in the trade than you know better.


Sent from my iPhone using Tapatalk

 

[bob15]

Google arc flash.

Yes, unplugging a motor under heavy load can cause one.

At high enough current and voltage, it can easily kill or seriously injure someone. Much more of an issue in industrial settings with 460V systems

yup.

As a side note, when I was traveling in India for work, the wall outlets all had a small switch that was to be thrown before unplugging anything, such the computer charging cord. If you didn't throw that switch there was a serious spark/flash. Crazy....

And India is 50hz, 230 vac

 

[majerus]

Put in a NEMA 14-50 and be done with it. That way if you get a welder, electric car or other high draw device you can support it.

 

[mike93lx]

Put in a NEMA 14-50 and be done with it. That way if you get a welder, electric car or other high draw device you can support it.

Or just run a separate circuit for all of those, you know, the proper way.
Also none of of those actually require a 14-50

 

[majerus]

If an ev can pull 40 amps for 6 hours a compressor can run for 5 mins . I have been running my 5hp compressor and cadet heater on that plug. Of course I don't run both at same time and unplug them when switching between each. Going to large cannot hurt anything and it's one run that way instead of being limited in the future run it larger to begin with.

 

[mike93lx]

If an ev can pull 40 amps for 6 hours a compressor can run for 5 mins . I have been running my 5hp compressor and cadet heater on that plug. Of course I don't run both at same time and unplug them when switching between each. Going to large cannot hurt anything and it's one run that way instead of being limited in the future run it larger to begin with.

My point is that it is a 120/240 plug, which compressors, heaters and ev chargers don't need.

There is no question about a compressor being able to run with one. The issue is code prohibits it and it is unsafe if it is ever unplugged, intentionally or accidentally, when running.

But I'm glad you are happy with your setup

 

[Viper98912]

Interesting read, learned a few things.

But a question - earlier in the thread it was stated that 10/2 wouldn't work for a 30 amp circuit and should be upped to 8g? How so?

 

[brewchief]

Interesting read, learned a few things.

But a question - earlier in the thread it was stated that 10/2 wouldn't work for a 30 amp circuit and should be upped to 8g? How so?

#10 nm-b is fine for a 30 amp circuit, the problem is motor circuits get sized via a table in the NEC and go by horsepower, IIRC a 5 hp motor requires wire rated for 35 amps, #10 thhn/ thwn in conduit would meet that or #8 nm-b.

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[u3b3rg33k]

No, a 5hp draws less than 30a when running.

If you unplug a motor when under load, it creates an arc flash hazard, which is very dangerous. Think super heated sparks. That's why high rated plugs are of a different style, called pin and sleeve where the prongs are shrouded

you would probably be just fine with the CS63 non-NEMA connectors too, if you're going to do it anyways. those are shrouded and rated for disconnection under full load (not that it's a good practice).

Is this "Arc flash" a real thing in the example we are talking about here ?

Please someone explain.

Marc

ever see an arc welder, or plasma cutter in use? that's what will happen to your plug if you unhook it while the magic is happening.

 

[atvkid4eva]

Lots of good info here! Thanks for all of that! So basically after reading through everything this is my conclusions...the current 30amp circuit has #10 nm-b wire. I can’t make out the words on the casing anymore, but I’m assuming it is not thhn because I don’t see a an insulator just a normal sleeve on the wire.. If this is true, I will need to replace this wire with #8 Nm-b since it is not run in conduit, but through the studs in the wall. I will leave the 30amp breaker in the sub panel? Or should I replace this with a 35amp breaker? I will then install a 30amp service shut off at the end of the new #8 Nm-b and hard wire the Compressor to that. Does this all sound correct and up to code? I want to do this the RIGHT way, I’d prefer not to burn my home shop down lol.

I also have another 50amp circuit in the shop, for a welder etc. so this would be dedicated to the compressor.

Also, what kind of wire would I run from the pressure switch to the 30amp shut off?

Thanks guys!

 

[mike93lx]

Lots of good info here! Thanks for all of that! So basically after reading through everything this is my conclusions...the current 30amp circuit has #10 nm-b wire. I can’t make out the words on the casing anymore, but I’m assuming it is not thhn because I don’t see a an insulator just a normal sleeve on the wire.. If this is true, I will need to replace this wire with #8 Nm-b since it is not run in conduit, but through the studs in the wall. I will leave the 30amp breaker in the sub panel? Or should I replace this with a 35amp breaker? I will then install a 30amp service shut off at the end of the new #8 Nm-b and hard wire the Compressor to that. Does this all sound correct and up to code? I want to do this the RIGHT way, I’d prefer not to burn my home shop down lol.

I also have another 50amp circuit in the shop, for a welder etc. so this would be dedicated to the compressor.

Also, what kind of wire would I run from the pressure switch to the 30amp shut off?

Thanks guys!

Thhn is individual conductors and must be run in conduit. The wires inside your nm-b are different.

Yes, change to 8/2 nm-b. You could run the 30a breaker or step up to a 40a (the next commonly available size.

From the disconnect to the comp, use a whip. Will either be flexible metal conduit or liquidtite. You'll need three pieces of 10 thhn for that (2 hots and a ground)

 

[atvkid4eva]

Thhn is individual conductors and must be run in conduit. The wires inside your nm-b are different.

Yes, change to 8/2 nm-b. You could run the 30a breaker or step up to a 40a (the next commonly available size.

From the disconnect to the comp, use a whip. Will either be flexible metal conduit or liquidtite. You'll need three pieces of 10 thhn for that (2 hots and a ground)

Okay, yes that explains why thhn needs to be run in conduit. Thanks for the clarification.

And the 8/2 nm-b will be with ground? So two hots and a ground, correct? What is the reason I don’t need 8/3, why do I not need a neutral in this application?

 

[brownbagg]

its just the three prong welding maching plug, its rated for fifty amps so it be plenty

 

[mike93lx]

Okay, yes that explains why thhn needs to be run in conduit. Thanks for the clarification.

And the 8/2 nm-b will be with ground? So two hots and a ground, correct? What is the reason I don’t need 8/3, why do I not need a neutral in this application?

A neutral is only required when the device has a need for 120v, like controls on an oven. Your comp is 240v only

 

[mike93lx]

its just the three prong welding maching plug, its rated for fifty amps so it be plenty

No it isn't. At least read the thread

 

[atvkid4eva]

A neutral is only required when the device has a need for 120v, like controls on an oven. Your comp is 240v only

Great, thank you for all the help! Greatly appreciated!

 

[mike93lx]

Great, thank you for all the help! Greatly appreciated!

No problem

 

[sberry]

What welder do you have? Could swap circuits. I might be tempted to leave it alone if it's in good shape.

 

[mike93lx]

What welder do you have? Could swap circuits. I might be tempted to leave it alone if it's in good shape.

Great point. The existing 10/2 would support the vast majority of home welding setups