120v to 240 switch for air compressor?

[Bmw4life]

Sorry if it's a noob question.

I found a compressor that I think will be the optimal choice for me.
I plan to use it for one purpose only, light sandblasting.

King Canada KC-3124V2 Air Compressor, Electric, 24 Gal. (29 US Gal), 150 PSI, 120/1/240/1 V

Portable Compressor Air Compressor, Electric, 24 Gal. (29 US Gal), 150 PSI, 120/1/240/1 V UAG293 KC-3124V2. Free Delivery on Orders Over $99

www.tenaquip.com

It's the biggest compressor I found that can be moved around.
Anything bigger will require hiring a moving crew...
It's the only compressor I found on wheels with 5hp.
I figure to take full advantage of it, it will require 240v, but by default comes with 120v.
I read the manual and I'm not sure what exactly is required to make it run on 240v?
I have the outlets, just not sure what adjustments need to be made on the compressor and how to make them.

If you make recommendations on other options, please keep on mind I'm in canada, so most of the US options won't be available here.

I know that many will say this is not enough for sandblasting, but even with Makita MAC5200 I could sandblast well enough for my needs.

I don't want to spend 2-3k for sandblasting a few small parts from time to time.

The most I was considering spending was for something like this

King Canada KC-5160V2 High Output Air Compressor, 50 Gal. (60 US Gal)

Stationary Compressor High Output Air Compressor, 50 Gal. (60 US Gal) UAK066 KC-5160V2. Free Delivery on Orders Over $99

www.tenaquip.com

But it's too heavy and cannot be moved by one person, which would significantly increase the cost for me.


That's why I think the first compressor will satisfy my needs. Just need to figure out how to switch to 240 volts. Do I need to hire an electrician?

 

[johnre]

I read the manual and I'm not sure what exactly is required to make it run on 240v?

Sometimes the instructions for configuring the wiring for 120 / 240 V isn't in the manual because they're motor specific, and one model of compressor may have had different motor suppliers sourced at various times. They leave it out of the manual because they don't want to have to update it each time they change suppliers.

Look for a tag or label on or near the motor itself. Typically, the wires are color coded and it's only a matter of hooking up the proper configuration called out.

And remember that it's sometimes not just the power cord that needs replacing; a piece of equipment factory wired for 120 V will often have only a SPST power switch mounted with it, which of course cuts off the hot leg but leaves the neutral connected. You ought to switch both hot L1 and L2 legs of a 240 V system so you don't leave the motor frame half hot all the time, and this may need a new DPST switch installed. Fortunately these switches are pretty generic, and you can usually find a replacement that fits the switch opening properly and even provides the important removable locking tab feature for child safety.

You won't have this issue if going from 240 V to 120 V; do watch the current rating on the switch and cord, however, as the current demand will double for 120 V.

My Delta dust collector is done this way - there's nothing printed in the manual about this. I had to look at the tag on the motor. And I also had to get a new DPST switch along with a new NEMA 6-15P equipped power cord.

If you make recommendations on other options, please keep on mind I'm in canada, so most of the US options won't be available here.

My advice applies to both Canada and the USA. We have the same power grid and mains voltages.

 

[Bmw4life]

Thanks for the advice, looks like it's no rocket science. I should be able to figure it out then, once I get the compressor.

The part about Canada vs US, I was referring to the air compressors.
I know Canada is just a blip compared to US and usually people will start suggesting a bunch of better compressors not available in Canada

 

[Retired dozer fixer]

Are you sure it’s 120V? Never heard of a 5hp motor on a compressor that wasn’t 240V. Or is it not 5hp

 

[Bmw4life]

I included the link above. Says 5hp

 

[Steve_P]

There is a current thread on this, where I say something similar to the below:

You are not going to cabinet blast with a suction gun, even using the smallest nozzle, for more than 30 seconds in each minute with a 6 CFM compressor. The compressor will never stop running, and you'll have to blast for maybe a max of 30 seconds, and then wait on it. And repeat.

10 CFM at 90 psi, is the absolute minimum, and the compressor will run all the time with the smallest nozzle in the blasting gun and barely keep up. This is based on my experience using a 10 CFM compressor with a blasting cabinet.

Blasting takes a LOT of air.

 

[rlitman]

I included the link above. Says 5hp

I saw, and I believe they're lying. Notice it says nothing about amp draw. Not on the web page, and not in the catalog. The actual HP is something we'd need to see the motor plate to know for sure, but my bet based on the 6CFM is probably around 2HP.

 

[u3b3rg33k]

I included the link above. Says 5hp

it's a lie. you get about 4CFM/horsepower, that's 6. 6/4 = 1.5hp.

5hp = 740w*5 /.8=4625W. at 120V that's 38 amps. you'd need a 50A circuit to run it.

the catalog page says "peak hp 5.5", which is probably some BS including inrush.

https://www.tenaquip.com/pdfs/bgt21/eng/0128.pdf?1619021160

EDIT: fixed my maths. I goofed

 

[cgrutt]

Manufacturer playing games with ratings. It says 5.5 Peak HP bet its actually closer to 1.5 HP. I had a floor buffer with 1.5 HP 120V motor and it would throw breakers constantly in use. You'd be drawing something like 35 amps constantly with a 5.5 HP motor at 120V most receptacles aren't rated for more than 20A. If you can check out compressor look at the plate on motor and see how many amps it is rated for that will give you better idea of actual HP. 1.5 HP at 120V should be about 9 amps.

 

[shibertus]

Based on the flow rating, this is more like a 1.5 or 2 HP compressor.

 

[mike93lx]

That's 5hp just like a shop vac is 6.5hp. Shenanigans.

Do you need it to be portable or just to be able to be placed by one person?

 

[The Cobbler]

yeah, it's one of the games. no way is it 5HP on a 120v circuit, and they don't even list the amps in the specs
there's no real advantage to swap it to 240 volts if it runs on a 120v circuit.

 

[nadogail]

Compressor manufactures advertise "Special Horse Power" ratings that remind me of the "Detroit Horsepower Ratings" of years long past.

Their ratings were not based on facts or reality.

 

[Bmw4life]

There is a current thread on this, where I say something similar to the below:

You are not going to cabinet blast with a suction gun, even using the smallest nozzle, for more than 30 seconds in each minute with a 6 CFM compressor. The compressor will never stop running, and you'll have to blast for maybe a max of 30 seconds, and then wait on it. And repeat.

10 CFM at 90 psi, is the absolute minimum, and the compressor will run all the time with the smallest nozzle in the blasting gun and barely keep up. This is based on my experience using a 10 CFM compressor with a blasting cabinet.

Blasting takes a LOT of air.

Ahhh I get that, I wish I could do 10 CFM, but the bigger compressor is 300 pounds. I'd be spending too much money to occasionally sandblast small parts like calipers, suspension components etc.
300 pounds is too much for me to carry into the basement lol

 

[Bmw4life]

it's a lie. you get about 4CFM/horsepower, that's 6. 6/4 = 1.5hp.

5hp = 740w*5 /.8=4625W. at 120V that's 38 amps. you'd need a 50A circuit to run it.

the catalog page says "peak hp 5.5", which is probably some BS including inrush.

https://www.tenaquip.com/pdfs/bgt21/eng/0128.pdf?1619021160

EDIT: fixed my maths. I goofed

Thanks for educating me guys, I had no idea the ratings were false. That's so frustrating.
I thought maybe on 220v it would produce 5.5hp

I found the motor sticker as you guys suggested

 

[mike93lx]

Thanks for educating me guys, I had no idea the ratings were false. That's so frustrating.
I thought maybe on 220v it would produce 5.5hp

I found the motor sticker as you guys suggested

Changing voltage doesn't increase power output, it just decreases the amp draw, allowing the use of smaller wiring/breakers, and decreasing voltage drop

 

[cgrutt]

2 HP (15x110/746)

 

[mike93lx]

2 HP (15x110/746)

That would be 100% efficient. Need to knock it back a bit, probably 25%

 

[cgrutt]

That would be 100% efficient. Need to knock it back a bit, probably 25%

Well Calc says 2.2 but I called it 2 lol. Also said earlier I bet its 1.5 so there's that.

 

[GeoBruin]

Ahhh I get that, I wish I could do 10 CFM, but the bigger compressor is 300 pounds. I'd be spending too much money to occasionally sandblast small parts like calipers, suspension components etc.
300 pounds is too much for me to carry into the basement lol

I spend a lot of time on this forum trying to debunk the myth that you can't blast with less than a 10HP compressor. The fact is, you can. No, you will not be able to use a large orifice gun, and yes, you will have to wait some, but not as much as most believe.

Here is a link to a post where I use a combination of some math, and some real world testing to show that you can get about 2 minutes of blasting for a 2 minute recharge cycle with compressor making not quite 5 cfm and with a smaller tank than you're looking at. If you follow my math you can plug in your own compressor specs and see what you'll be looking at. Also, note this is with the TP Tools medium jet and tip kit, which is 1/4". They also offer a small kit which would further extend your blasting time.

The Abrasive Blasting Resource Thread

I think I kind of, sort of, understand what you're getting at, but I think most people here reading about blasting understand the basic principles involved, including the concept of a pressure regulator. When you and everyone else here talks about a compressor not being able to "keep up" with a...

www.garagejournal.com

 

[Steve_P]

Yeah, that's ~2 "real" HP. 6 CFM rating is the key parameter and it's nowhere near enough.

OP, If you have small parts that need blasting, try and find a local powdercoating shop as many of them offer the service.

 

[Bmw4life]

Yes I agree blasting with less than 10cfm is fine. Like I said at the beginning, I was happy enough blasting with Makika Mac 5200, 6.5 CFM @ 90PSI ans 5 gallon tank.

Unfortunately not many sandblasting and powdercoating shops around me.
I'm building my own powdewcoating with a used electric smoker and bought a small powdercoating cabinet.

I guess there's better portable options out there.

Looks like this guy can produce 10 cfm for real, though a bit steep in price.

https://www.grainger.ca/en/product/AIR-COMPRESSOR-3-0-HP-240V-135-PSI/p/GGF1NNF7

Someone else managed to buy it for $600 with a friend's discount on this forum, that'd be a wicked deal

I'm gonna see if I can find anything else portable for 10 cfm.

 

[u3b3rg33k]

Thanks for educating me guys, I had no idea the ratings were false. That's so frustrating.
I thought maybe on 220v it would produce 5.5hp

I found the motor sticker as you guys suggested

a 5HP motor will pull around 22 amps at 240v.

Yeah, that's ~2 "real" HP. 6 CFM rating is the key parameter and it's nowhere near enough.

OP, If you have small parts that need blasting, try and find a local powdercoating shop as many of them offer the service.

it's important to remember that compressor horsepower doesn't do useful work, CFM does. horsepower is a more commonly used rating (cars!) so it "makes sense" to people. I guess.

 

[Bmw4life]

I guess another good option

Campbell Hausfeld Air Compressor, 30 Gallon Portable 10.2CFM 3.7HP 208-230V 1PH (VT6104)​

Biggest HP and portable size I could find.

30 gallon is pretty good and 10 cfm seems real in thus case.
Just a little steep, but at least it's portable.

 

[mike93lx]

Make sure you don't ignore duty cycle.

 

[u3b3rg33k]

don't carry it into the basement, buy a longer hose.

 

[micromind]

Every AC induction motor (like the one on that compressor) can produce more peak HP than it can while running under normal load. This peak will be anywhere from 150 to 500% depending on the design.

In this case, the motor can produce about 1.5HP continuously but it can also produce 5HP maximum. If it's loaded to 5HP, it will either trip the overload or simply burn up in less than a minute.

An actual 5HP compressor will produce roughly 20 CFM@100PSI.

As far as installing a dual-voltage switch, it's not all that difficult. Depending on how the windings are connected, you'll need either a 2 or 3 pole double-throw switch with contacts rated at least the 240 volt amps. It does not need to be HP rated because it is not used to start and stop the motor.

If you can post the connection diagram, I'll post how to hook it up.

 

[johnre]

I guess another good option

Campbell Hausfeld Air Compressor, 30 Gallon Portable 10.2CFM 3.7HP 208-230V 1PH (VT6104)​

Yes, this one is portable and a for real 10.2 CFM - the manufacturers often play games on HP ratings, as others have indicated, but they don't seem to mess with SCFM ratings as long as they're quoting the delivery at 90 PSI. You'll probably need help to get it into the basement, but look at it this way - once there, you're probably not going to move it, as it will be staying wherever the power outlet is located.

And note it can't be converted to 120 V, the motor draws 15.7 A at 240 V.

I found the motor sticker as you guys suggested

This motor is 120 V only, FWIW. Yes, it is dual voltage, as evidenced by the separate 110 V / 220 V listings.

 

[cgrutt]

This motor is 120 V only, FWIW.

Huh? How you figure?

 

[johnre]

How you figure?

On second look, I'm incorrect - the top half of the motor tag clearly lists 110 V, the bottom half 220 V. Mea culpa, post corrected.

 

[Sumboodie]

I included the link above. Says 5hp

Can't be 120v. That would need a 40 amp outlet, which doesn't exist.

 

[mike93lx]

Can't be 120v. That would need a 40 amp outlet, which doesn't exist.

Siemens makes up to 70a single pole breakers. Not sure where other brands go up to, but a 40a SQD QO is only about $10. You definitely can do 40A+ for a 120v circuit

 

[johnre]

You definitely can do 40A+ for a 120v circuit

True, but other than for RV hookup, usage is uncommon.

And there is only a NEMA recpticle and plug spec for 120 V single pole operation up to 50 A.

Finally, you're not going to even find an air compressor that goes beyond 20 A @120 V. Above that, manufacturers jump to 240 V operation only.

 

[mike93lx]

True, but other than for RV hookup, usage is uncommon.

And there is only a NEMA recpticle and plug spec for 120 V single pole operation up to 50 A.

Finally, you're not going to even find an air compressor that goes beyond 20 A @120 V. Above that, manufacturers jump to 240 V operation only.

No argument on any of that

 

[Bmw4life]

Found this 5hp, 10 cmf, 30 gallon compressor at a very reasonable price of $500, which is 1/3 of what the new ones cost.
Not sure if it's a good idea to buy a used compressor or it's worn out by now?

 

[The Cobbler]

again it's a bogus 5HP. it draws 14 amp so at best it's about 1.5 hp
it will be noisy too as it is direct drive & oiless.
personally I would not pay any where near the asking price for that unit

 

[Bmw4life]

Ahhh I missed the 14 amp part, I thought CFM rating was legit. Dang!

 

[rlitman]

again it's a bogus 5HP. it draws 14 amp so at best it's about 1.5 hp
it will be noisy too as it is direct drive & oiless.
personally I would not pay any where near the asking price for that unit

It's 240V, so more like 3HP for 14A. Which makes it probably closer to 8 CFM. But the bigger lie here is about duty cycle. CFM is only meaningful if you can run the pump continuously. Oilless compressors like this will burn up if you do that. Figure on a 25% duty cycle at best, so now you're down to about 2CFM for the purposes of blasting.

I had something like this (240V twin oilless) in Craftsman red over a 60 gallon tank. It was by far the loudest compressor I've ever heard. I also paid under $200 for it used, and broke even when I sold it. $500 for that is just plain nuts.

 

[The Cobbler]

good point on the 240v. I missed that ! but still wouldn't buy it .

 

[whateg01]

Are you sure it’s 120V? Never heard of a 5hp motor on a compressor that wasn’t 240V. Or is it not 5hp

It's 5.5 peak hp. Manual I found says 15A @ 240 and 7.5A @ 120