Plug wired to compressor

[wyliesdiesels]

The panel should have a minimum of 30A (Sparkies, check me here) breaker for the compressor.

30a breaker will probably hold but could also nuissance rip

since it will be hardwired, breaker can be max 2.5x of FLC, 70a for 5HP

 

[sparky 1971]

It would not surprise me if the electrician the OP hires to fix this has an additional "small job" charge (whether outright stated or just in the price).

Most contractors are going to have a minimum, usually two hours; I have a one hour minimum, but if it's an hour or less there is a $50 trip charge. The problem is getting something like this worked into the schedule.

 

[Cruzan80]

30a breaker will probably hold but could also nuissance rip

I was simply basing it off the Quincy 325 I have, with a Baldor 5HP that is also a few feet away from the compressor. I haven't had an issue with a 30A breaker on mine, but couldn't remember if it had to upsize due to being a motor to meet code.

 

[jblnut]

If the HP is more than about 3, it will need to be hardwired to a disco, unless panel is in sight of and not more than 50' from compressor

Do all air compressors over 3hp have to be hardwired based on likely immobility or another reason ? I have a 60gal with a 5hp motor that I move around often from my shop to another shed and sometimes in the back of the farm truck to take to a shed to air up a large tire. It is wired with the same plug used on my welders so it can be plugged in anywhere we have 240v on the farm.

 

[mike93lx]

Do all air compressors over 3hp have to be hardwired based on likely immobility or another reason ? I have a 60gal with a 5hp motor that I move around often from my shop to another shed and sometimes in the back of the farm truck to take to a shed to air up a large tire. It is wired with the same plug used on my welders so it can be plugged in anywhere we have 240v on the farm.

The plug isn't rated for 5hp, so it isn't compliant, but if it works...

 

[jblnut]

The plug isn't rated for 5hp, so it isn't compliant, but if it works...

I see. Well then I suppose the 7.5hp motors on all my farm augers with 6-50 and 10-50 style plug/recpts are also non-compliant.

Just because it works doesn’t mean it’s a good idea though. Some have been in service for decades. Huh. We’ve never had an issue with anything getting melty at the plug/receptacle itself but I’ve honestly never felt them when they’ve been running for a while. I have to mix feed this afternoon and I’ll temp gun the plug for funsies. Again, doesn’t make it compliant ……. Leave it to GJ to properly inform a guy once in a while lol.

What’s a recommendation for a plug system that can support up to a 7.5hp motor ?

 

[CGT80]

A 50a 250v welder plug will absolutely work with an average air compressor. I did it for a long time.

Code and what mechanically works are two different things.

My WABCO compressor has a 5hp baldor motor rated at around 27.5 amps. It is also a 184 frame with a 1.375" shaft.....it is an older motor. It flashes 165 amps at start up across my green lee and klein meters.

Just do not unplug it or plug it in without the compressor switched off.

When I rebuilt the garage, I installed a motor starter and #6 wire directly to the air compressor and direct wired my tig welder on #4 wire and a 100 amp breaker. It can pull 104 amps at 230v per the nameplate........voltage was listed lower in 1963 when it was built. When it had a 50a 250v plug, I had to avoid welding at full output (460 amps).

For the OP, electricity isn't magic. do some reading or watch some videos on the basics. Electricity is very mechanical, just like plumbing on a vehicle. You just need to know some basic rules and how it works and how to fit 10 pounds of wire in a 5 pound box. With years of doing it professionally, I figured it out.

If you are not in dire need of the air compressor, research first. You could do better than the hack you already paid or at least know how a pro should do it.

Decide whether you want what works or what code requires....code is easy to do in your case, but replacing that conduit with cord is something you could do dyi that is very easy.

With the power off.....assuming that is a sub panel and there is a breaker upstream to shut it off, it is easy mechanical work. if you can work off the receptacle box and not get in the panel, then it is easier yet.

The problem is finding a sparky or good all around construction guy who will do it right and not charge an arm and a leg. It is very basic stuff. On one side you have wasted money if you hire someone and on the other you have some liability and potential for injury or fire if you screw it up bad. Tough call.

 

[mike93lx]

I see. Well then I suppose the 7.5hp motors on all my farm augers with 6-50 and 10-50 style plug/recpts are also non-compliant.

Just because it works doesn’t mean it’s a good idea though. Some have been in service for decades. Huh. We’ve never had an issue with anything getting melty at the plug/receptacle itself but I’ve honestly never felt them when they’ve been running for a while. I have to mix feed this afternoon and I’ll temp gun the plug for funsies. Again, doesn’t make it compliant ……. Leave it to GJ to properly inform a guy once in a while lol.

What’s a recommendation for a plug system that can support up to a 7.5hp motor ?

I hear you. The biggest risk that I'm aware of is unplugging the motor when under load and the arcing that can happen.

There are (expensive) pin and sleeve plugs that can do this.

Whats the application for a 7.5hp motor that makes it need to be on a plug?

 

[wyliesdiesels]

Do all air compressors over 3hp have to be hardwired based on likely immobility or another reason ?

as said above, the issue is the plug and recept ratings..... if you can find a plug and recept rated for the HP of the motor, then you are good to go.... they do exist up to certain ratings, but they are expensive... cheaper to hardwire especially for equipment you dont need to move on a regular basis.

 

[wyliesdiesels]

I see. Well then I suppose the 7.5hp motors on all my farm augers with 6-50 and 10-50 style plug/recpts are also non-compliant.

the issue comes from unplugging them while running. say you have an emergency and need to shut the motor off right away and dont have time to run to the breaker panel. pulling that plug can expose you to a nasty arc flash....

also the 10-50p is non-grounded 120/240v rated so of course its the wrong plug for a 240v motor.

 

[alfredeneuman]

There are (expensive) pin and sleeve plugs that can do this.

Whats the application for a 7.5hp motor that makes it need to be on a plug?

There are many different brands, voltage, and amp ratings of pin and sleeve recps. and plugs all with different part numbers. If you google "pin and sleeve receptacles" you'll get the horsepower ratings of each.

 

[mike93lx]

There are many different brands, voltage, and amp ratings of pin and sleeve recps. and plugs all with different part numbers. If you google "pin and sleeve receptacles" you'll get the horsepower ratings of each.

I did some searching and wasn't quickly coming up with a 250v single phase rated for 7.5hp. Surprised me that a 125v rated one was easy to find.

I'm sure they are out there, but I wanted to include a link to one and couldnt

 

[Cruzan80]

also the 10-50p is non-grounded 120/240v rated so of course its the wrong plug for a 240v motor.

The correct (grounded) option would be the 14-50, correct?

I actually just saw a pin/sleeve plug at an ES yesterday. Half tempted to buy it, but couldn't find a matching receptacle for sale.

Edit, here is a 7.5HP rated one (just plug) from Mcmaster Carr ($306)

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

 

[jblnut]

I hear you. The biggest risk that I'm aware of is unplugging the motor when under load and the arcing that can happen.

There are (expensive) pin and sleeve plugs that can do this.

Whats the application for a 7.5hp motor that makes it need to be on a plug?

Mostly grain augers that move from bin to bin and site to site. This one is a 10hp on a 10-50.

as said above, the issue is the plug and recept ratings..... if you can find a plug and recept rated for the HP of the motor, then you are good to go.... they do exist up to certain ratings, but they are expensive... cheaper to hardwire especially for equipment you dont need to move on a regular basis.

I’ve done some looking on the internet’s and yeah, they’re quite spendy. Multiply that by 6 augers and around 20 places to plug them into and 3 extension cords and we’re up to a decent used Ridgeline in plugs and receptacles.

the issue comes from unplugging them while running. say you have an emergency and need to shut the motor off right away and dont have time to run to the breaker panel. pulling that plug can expose you to a nasty arc flash....

also the 10-50p is non-grounded 120/240v rated so of course its the wrong plug for a 240v motor.

I’ll do some looking around but I don’t think we have a single 1ph motor with 4 wires running to it. I know for sure the augers we have running all have either a 6-50 or 10-50. Not saying it’s correct but it’s what’s here and has been working for decades.

Every receptacle is within less than 3’ of the breaker panel. The breaker is quicker to flip off than the plug is to pull. I don’t ever remember pulling the plug when there is power to the plug. I’m quite sure all the breakers in the bin panels are rated for switch duty.

 

[sparky 1971]

The correct (grounded) option would be the 14-50, correct?

For a 50 amp 250 volt it would be a 6-50. 14-50 is 120/240 with a ground but neither of those are supposed to be connected to a 7-1/2 HP motor though it is done quite often on farms (usually with the universal 10-50 two twenny plug).

I actually just saw a pin/sleeve plug at an ES yesterday. Half tempted to buy it, but couldn't find a matching receptacle for sale.

Edit, here is a 7.5HP rated one (just plug) from Mcmaster Carr ($306)

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

 

[PCustoms]

Since when does NEC apply to farms?

 

[wyliesdiesels]

The correct (grounded) option would be the 14-50, correct?

for a 4-wire 120/240v plug yes. but you dont need that for a 240v motor. 6-50p would be the correct one

 

[wyliesdiesels]

Edit, here is a 7.5HP rated one (just plug) from Mcmaster Carr ($306)

that is for 3Ø not 1Ø

 

[mike93lx]

Since when does NEC apply to farms?

They are just like utilities.

And have pigs. Don't mess with a dude that has pigs

 

[Cruzan80]

for a 4-wire 120/240v plug yes. but you dont need that for a 240v motor. 6-50p would be the correct one

Yes, was meaning 120/240. I have 6- plugs on all of my equipment in the garage, as nothing needs the neutral.

Thanks for the catch on the plug, was just trying to see quick HP ratings. Figured it was at least a jumping off point for finding them for those who want to know what the cost.

 

[gimpyrobb]

Shame you're in the opposite corner of Ohio, I could have helped.

 

[mm08822]

Since when does NEC apply to farms?

Since article 547. It applies to all of the permanent wiring, which would include the recepts. 6-50R or even 14-50R would have been the correct receptacle to install (neglecting hp rating). OP wouldn't need to connect anything to the neutral if he was using 14-50P.

However, what you plug into the recepts is another story.

 

[PCustoms]

Since article 547. It applies to all of the permanent wiring, which would include the recepts. 6-50R or even 14-50R would have been the correct receptacle to install (neglecting hp rating). OP wouldn't need to connect anything to the neutral if he was using 14-50P.

However, what you plug into the recepts is another story.

 

[mike93lx]

Since article 547. It applies to all of the permanent wiring, which would include the recepts. 6-50R or even 14-50R would have been the correct receptacle to install (neglecting hp rating). OP wouldn't need to connect anything to the neutral if he was using 14-50P.

However, what you plug into the recepts is another story.

Boooooo

 

[sparky 1971]

Since article 547. It applies to all of the permanent wiring, which would include the recepts. 6-50R or even 14-50R would have been the correct receptacle to install (neglecting hp rating). OP wouldn't need to connect anything to the neutral if he was using 14-50P.

However, what you plug into the recepts is another story.

You're no fun.

 

[mm08822]

 

[mike93lx]

You're no fun.

I bet he has lines painted on the floor in front of his panel

 

[PCustoms]

I bet he has lines painted on the floor in front of his panel

At minimum a sticker

 

[mm08822]

 

[alfredeneuman]

Every receptacle is within less than 3’ of the breaker panel. The breaker is quicker to flip off than the plug is to pull. I don’t ever remember pulling the plug when there is power to the plug. I’m quite sure all the breakers in the bin panels are rated for switch duty.

Why not hardwire them then and let the breakers be the required disconnects.

 

[PCustoms]

Why not hardwire them then and let the breakers be the required disconnects.

How's that work when he needs the auger across the farm?

 

[wyliesdiesels]

I bet he has lines painted on the floor in front of his panel

Ive got red tape on the floor in front of my panel because my techs kept stacking ladders in front of the panel

 

[mike93lx]

Ive got red tape on the floor in front of my panel because my techs kept stacking ladders in front of the panel

At your house?

 

[Norcal]

I am retired but my shop panelboard is behind a door if access is needed, just close the door. now the panelboard in the back room would make a OSHA inspector **** their pants & a write up but they don't have jurisdiction there.

 

[alfredeneuman]

Multiply that by 6 augers and around 20 places to plug them into and 3 extension cords

I failed to see this....Sorry.

 

[MovingAlong]

I will repeat it again. I DON'T FOOL WITH ELECTRICITY BECAUSE I DON'T HAVE ANY KNOWLEDGE OF IT. I know I look like a fool and that I am possibly trolling the people on here that have helped me in the past, which I wouldn't do. I paid a professional electrician to wire it in for me and this is what he gave me. It didn't look right to me, so I wanted to see what I needed to do to make it right. It is apparently not just a new wire I can make.

It seems I will need to call another electrician to do this right. If someone can tell me what it is exactly that I need so it doesn't happen again, I would appreciate it. I will move the compressor far enough from the panel that the door opens completely. I am going to put a picture of the receptacle on here in case I need that replaced as well. Thanks

That receptacle appears to be a NEMA L6-20, which is only rated for 20 amps while your motor draws 22 amps. Those letters/numbers should be molded around the face of the receptacle.

If you can confirm that, you'll also want your new electrician to verify if you have the right breaker and wiring to support upgrading to an L6-30 (or some other suitably higher rated plug) for 30 amps or more. Hardwiring does seem like the better option though. Find a new guy and talk with him about your concerns.

As many have alluded to already, there is some overlap between what works and what's right. Kudos to you for wanting it done right.

 

[jblnut]

Why not hardwire them then and let the breakers be the required disconnects.

All 15hp+ are hardwired and they’re a pain so they don’t move often. The 7.5hp and below all have plugs and the 10hp are hit and miss but most have 6-50 or 10-50 plugs.

How's that work when he needs the auger across the farm?

Yeah that’s the thing. It’s quite a bit easier to flip a switch (or breaker), unplug and move it than rewire things.

I failed to see this....Sorry.

It’s all good

 

[jblnut]

They are just like utilities.

And have pigs. Don't mess with a dude that has pigs

I don’t have pigs but I do own a couple excavators……

 

[mike93lx]

Yeah that’s the thing. It’s quite a bit easier to flip a switch (or breaker), unplug and move it than rewire things.

Why don't you just buy more augers?







/s

 

[jblnut]

Why don't you just buy more augers?







/s

Because they put wheels on them and make us think they’re portable

And to use them for 16hrs a year to unload a bin doesn’t really warrant an auger per bin

That 10” auger I pictured was $9300 ….. plus the motor. I’d need a quarter million in augers and motors