Need help converting 3 phase air compressor to single phase

[zruvalcaba]

Hello there...I'm a new member that has a problem with a compressor that I recently purchased and would like a hand from some experts here on a possible solution.

I recently purchased an Ingersoll Rand 5 HP, 60 gallon, 3 phase air compressor from a shop that was going out of business. I picked up the 4 month old compressor for about half of what they're going for new at Northern Tool. My problem is that the unit is 3 phase and I live in an area that does not have 3 phase power coming to my breaker.

What I have decided to do is replace the motor with a single phase unit. I contacted Ingersoll Rand and they can have a single phase motor delivered to my local IR distributor for about $500. That still puts me at a $100 advantage to buying it new and I can probably sell the old 3 phase motor. The tech support person at IR told me that the magnetic starter would not be required on the new single phase motor. Fine. I suppose I could probably resell that too.

My question is, has anyone done a similar conversion before? Is she correct, is the motor all I need to replace? Just a straight swap? She mentioned that I would have to wire the pressure switch from the compressor to the motor...currently the pressure switch runs to the mag starter. Motor to starter, pressure switch to starter, starter to breaker. So now I suppose I'll be going pressure switch to motor and then motor directly to breaker? Do these single phase motors have an On/Off switch? I'm a bit over my head and have my father-in-law helping me out...he's competent...built his own house from scratch...but some direction would be appreciated. I've attached some pictures of the existing setup for reference. Thanks a ton in advance....

 

[cwlo]

Baldor makes two different 5hp single phase motors. One requires a magnetic starter, the other not. I bought a 5hp 3ph Champion compressor. I also purchased a new 5hp baldor from an Ebay seller for about $320 if I remember correctly. They should still be on there. I then used the 3ph magnetic starter since it can also be used for single phase 220. A few wiring changes (one less wire to use, and I also used bigger wire since there is more amp draw on single phase).

Now, you can purchase the other 5hp motor that doesn't require the magnetic starter. You would then need to hook the motor wires to the pressure switch. You just have to make sure the pressure switch can handle the amperage of the motor. However, compare the two motors, because this motor appears to be less stout than the true 5hp motor above. Its should be fine for a home shop though. In either case, the motor is turned on when the pressure switch trips due to the air pressure going below setpoint. Motor will run until high end pressure is reached.

Good luck,

Chris

 

[zruvalcaba]

Thanks for the quick reply Chris. I'd actually prefer a Baldor over the WEG Ingersoll Rand model if for no other reason than just because the Baldor is made In the USA whereas the WEG is made in Brazil.

I saw these on Ebay:
http://www.ebay.com/itm/NEW-SURPLUS...ultDomain_0&hash=item2a15268507#ht_500wt_1216
http://www.ebay.com/itm/NEW-5-HP-BA...ultDomain_0&hash=item2eb8713ddc#ht_500wt_1216
http://www.ebay.com/itm/BALDOR-L149...aultDomain_0&hash=item19c9be1985#ht_571wt_966

They all have the 184T frame whereas mine has the 182T frame. From what I understand, both of these frame types are similar and you can use either?

Knowing nothing about electrical, I'm hesitant to buy a motor that is not being sold to me by Ingersoll Rand. But I've attached the manufacturer's badge which is on the current WEG motor....would any of the above motors work as a direct replacement to what I have now?

Now, how do you know if it requires the mag starter or not? Does it even matter since I already have the mag starter anyway?

 

[cwlo]

Check out weco-group on ebay. They are a Baldor reseller. They can tell you which motor will match up with your compressor. Looks like your motor is 3250rpm which is faster than the one my needed. Also need the shaft length and size.

As far as the mag starter, you need to see if yours can be used for single phase 220. You will need to find the amp draw on the motor, and see if the magnetic starter can handle that amperage. The magnetic starter is two components; the top has the relay that turns the motor on/off. The bottom is the thermal overload that is either adjustable, or has replaceable heaters that have to match the amp draw of the motor. Bottom line, is you need to select the replacement motor, and then see if your current magnetic starter can be used as is, or modified, or replaced.

Good luck,

Chris

 

[theoldwizard1]

They all have the 184T frame whereas mine has the 182T frame. From what I understand, both of these frame types are similar and you can use either?

Maybe. Depends if the mounting holes are slotted and how big are the slots.

From this chart, you will see there is a difference between a 182T and 184T frame is 1" on the 2F dimension.

I personally would have no issue buying a motor from a source other than IR. I would contact Baldor to try and find what the difference is between those 3 models and which would be better for your application

I think i would leave the magnetic starter (also called a contactor) is a type of super heavy duty relay. I think I would reuse it as the contacts on the pressure switch are not likely to be able to handle the starting current of that 1P 5HP motor (unless you can confirm otherwise).

 

[zruvalcaba]

Ok, you guys are talking to an incompetent here...my hobbies are restoring firearms...not dilly dallying with mechanical equipment....I'm getting lost.

Regardless of the mag starter and the pressure switch...I need a new motor, correct? The 3 phase model just aint gonna work. So perhaps I should start there....

Somebody just to tell me...."buy this model here, it'll work as a replacement to what you have now" and give me a link? Isn't it that simple?

Thanks,
Zak

 

[zruvalcaba]

Maybe. Depends if the mounting holes are slotted and how big are the slots.

It sure looks like the holes are slotted. Check out this pic here:

Looks like 184T will work...right?

I personally would have no issue buying a motor from a source other than IR. I would contact Baldor to try and find what the difference is between those 3 models and which would be better for your application

I have no problem either, I'm just concerned because I have no idea what the hell I'm doing. I just want my compressor to work.

I think i would leave the magnetic starter (also called a contactor) is a type of super heavy duty relay. I think I would reuse it as the contacts on the pressure switch are not likely to be able to handle the starting current of that 1P 5HP motor (unless you can confirm otherwise).

Well, it's not in the way...I certainly won't be removing it. Can you see on the Siemens badge of markings in the image above if it's compatible for single phase applications?

 

[zruvalcaba]

Called Baldor and they recommended L1409T which is this one here...and the guy is 45 minutes from my house:

http://www.ebay.com/itm/BALDOR-L149...aultDomain_0&hash=item19c9be1985#ht_619wt_966

List price he gave me was $904 so for $225 that sounds like a smokin' deal.

 

[mike13u]

You can do this alot easier (maybe not cheaper, but easier) and help resale by just buying a 7.5hp rotary phase converter and placing it on the wall between the machine and your single phase line. Should be around $500-600 for the phase converter. Nothing on that nice comperessor will need to be changed or adjusted.

You would also be able to power any other 3-phase machines that you buy in the future (not at the same time depending on the HP) with the one phase converter.

I have two 3-phase items in my garage and both are run on a 10hp rotary phase converter. Very easy to set up. Clear instructions provided.

Why tear up a nice machine?

 

[Charles (in GA)]

Not sure why IR told you that you don't need a starter. Generally FULL 5 hp motors and up use a starter and it will be better in the end. If the motor does not have a internal overheat and reset (evidenced by a reset button on the end of the motor you install) you absolutely need the starter for overload protection.

Keep the magnetic starter, otherwise you will be cooking pressure switches as they are not designed to carry the full current of a 5 hp motor. The starter you have can be used, just that you will not use one of the vertical contact paths, probably leave the middle one not connected. You will also need to change out the heater coil in it to have the correct one for the new motor you have. (the heater coil is what the two red wires on the lower left of the starter are connected to) There should be a chart inside the cover that will relate motor data plate amps to heater coil number. If not, since this is a new starter, you should be able to find the info online.

You may also need to change the coil in the starter, cannot read the info on the coil sticker.

If you are not familiar with wiring stuff, find someone who is truly familiar with doing this, otherwise it will get messed up in a hurry.

Charles

 

[Charles (in GA)]

You can do this alot easier (maybe not cheaper, but easier) and help resale by just buying a 7.5hp rotary phase converter and placing it on the wall between the machine and your single phase line. Should be around $500-600 for the phase converter.

You would also be able to power any other 3-phase machines that you buy in the future (not at the same time depending on the HP) with the one phase converter.

I have two 3-phase items in my garage and both are run on a 10hp rotary phase converter. Very easy to set up. Clear instructions provided.

Why tear up a nice machine?

Swapping motors does not "tear up" a compressor. IR sells this same unit in single phase, all he is doing is re-configuring it to single phase. Cannot see how installing, setting up, wiring up and connecting a rotary phase converter would be "easier" than simply swapping the motor and re-configuring the starter. Never has made much sense to me to have a compressor on a rotary converter. You go out to the shop in the morning to work all day, you start up the converter, let it RUN all day long so that when you need air for a blow nozzle, impact, lift, whatever, you have power to run the compressor.

Its different with mills and lathes. When you use a mill or lathe, you can start the converter, do your work, and then shut it down. With a compressor, it needs power to start anytime it wants to.

Charles

 

[zruvalcaba]

I looked at the rotary phase converter option....again, I'm not a machinist....just a guy that bought a 60 gallon, 2 stage compressor to power my blast cabinet and a couple of pneumatic grinders. With that said, I will most likely never have the need for a Bridgeport or anything of the sort. If I can get a $250 replacement single phase motor...and be good with that....I'd be happy.

Is the Baldor I linked to going to work? That's $225 and I can pick it up. That would allow me to skate away from this in good shape price-wise.

 

[zruvalcaba]

Not sure why IR told you that you don't need a starter. Generally FULL 5 hp motors and up use a starter and it will be better in the end. If the motor does not have a internal overheat and reset (evidenced by a reset button on the end of the motor you install) you absolutely need the starter for overload protection.

Keep the magnetic starter, otherwise you will be cooking pressure switches as they are not designed to carry the full current of a 5 hp motor. The starter you have can be used, just that you will not use one of the vertical contact paths, probably leave the middle one not connected. You will also need to change out the heater coil in it to have the correct one for the new motor you have. (the heater coil is what the two red wires on the lower left of the starter are connected to) There should be a chart inside the cover that will relate motor data plate amps to heater coil number. If not, since this is a new starter, you should be able to find the info online.

You may also need to change the coil in the starter, cannot read the info on the coil sticker.

If you are not familiar with wiring stuff, find someone who is truly familiar with doing this, otherwise it will get messed up in a hurry.

Charles

Thanks for the reply...I think I'm going to start with the motor and then figure out the starter.

 

[cwlo]

If Baldor said the 1409T, they are the experts and then that's the one you need.

Next step is to get us a better picture of that Siemens magnetic starter so we can see the fine print.

Chris

 

[zruvalcaba]

If Baldor said the 1409T, they are the experts and then that's the one you need.

Next step is to get us a better picture of that Siemens magnetic starter so we can see the fine print.

Chris

I'm going to call IR tomorrow morning and just triple check the shaft diameter, length, and keyway on the existing model that I have here. If it's the same 1 1/8" x 2 3/4" x 1/4", then I'll pick up that Baldor for sure. Unless you guys think there's no need and I should just pull the trigger on it?

The fine print on the Siemens mag starter was VERY small. I'll see if I can get a better picture of it tonight.

Zak

 

[zruvalcaba]

Just called Baldor again and they said that the L1409T does not require a magnetic starter.

Zak

 

[cwlo]

Here's some good info that might be helpful.

http://www.temcoindustrialpower.com/product_selection.html?p=compressor-conversion-selection-guide

 

[Charles (in GA)]

The fine print on the Siemens mag starter was VERY small. I'll see if I can get a better picture of it tonight.

Zak

Use the Macro on your camera (the little flower looking thing is the macro symbol).

Charles

 

[Charles (in GA)]

Just called Baldor again and they said that the L1409T does not require a magnetic starter.

Zak

Better stock a spare pressure switch then, it won't hold up to the amperage of that motor. No, the motor may not need one, but the entire assembly will thank you for it.

Charles

 

[zruvalcaba]

Better stock a spare pressure switch then, it won't hold up to the amperage of that motor. No, the motor may not need one, but the entire assembly will thank you for it.

Charles

Point taken, thanks Charles. With that said, here's a closeup of the fine print on the starter:

 

[zruvalcaba]

Here's some good info that might be helpful.

http://www.temcoindustrialpower.com/product_selection.html?p=compressor-conversion-selection-guide

Wow, that's like the definitive guide to air compressor motors, phase converters, and mag starters there. Amazing. I'm still a little foggy on everything but it's good to know that replacing the starter isn't all that costly. If I can pick up a motor for sub $300 and worst case scenario I have to get a new starter...I'm still ahead by about $300 versus buying the compressor new. I can live with that.

Zak

 

[930dreamer]

Let us know how every things turns out, I like closure.

 

[zruvalcaba]

Just got an email back from the seller of the Baldor motor on Ebay. They are indeed 45 minutes from my house and said that they can hook it up to verify that it works. Unless there are any objections, I suppose this is the motor that I'll buy....

Zak

 

[lametec]

Your starter is only rated for a 3HP on 240V 1ph, so technically you'll be overloading it running a 5HP motor off it. With that said, running it straight off the pressure switch will probably overload it in a similar manner, and life expectancy of them both will probably by very similar.

 

[Travis E.]

Your starter is only rated for a 3HP on 240V 1ph, so technically you'll be overloading it running a 5HP motor off it. With that said, running it straight off the pressure switch will probably overload it in a similar manner, and life expectancy of them both will probably by very similar.

I agree with you. Putting HP asside I would use that starter because FLA on the new Baldor motor is 23 and the starter is rated at 25 amps.

 

[zruvalcaba]

So does that mean I need to replace the starter as well? Any recommendations? Are there any with on/off buttons?

Zak

 

[PT Doc]

You can try a u frame adapt o mount or adjustable steel motor mounts from grainger pg 88.

 

[PT Doc]

Another option is to just sell the while unit as you bought it and just get one the way you want it. Just a thought.

 

[All Systemz]

If you run it right off the pressure switch, it will burn out probably the third time it tries to start up again. That's why you need to use the magnetic starter.
In my opinion you can use the existing starter, the rating say's FLA 25. I just did this swap from 3 phase to single on my Curtis. The FLA on my motor say's 26A but while running it pulls 16A and ramps up to 19A when it cuts off at 150 psi.
I found my motor used for $150.00 on Craigslist, you should give that a look.
Also, could you post the spec's on your IR pump?

 

[zruvalcaba]

Another option is to just sell the while unit as you bought it and just get one the way you want it. Just a thought.

I tried doing that through Craigslist and haven't received any bites.

 

[zruvalcaba]

If you run it right off the pressure switch, it will burn out probably the third time it tries to start up again. That's why you need to use the magnetic starter.
In my opinion you can use the existing starter, the rating say's FLA 25. I just did this swap from 3 phase to single on my Curtis. The FLA on my motor say's 26A but while running it pulls 16A and ramps up to 19A when it cuts off at 150 psi.
I found my motor used for $150.00 on Craigslist, you should give that a look.
Also, could you post the spec's on your IR pump?

Ok, so the general consensus seems to be to use the existing starter? Worst case scenario...I buy a new one down the road...they don't seem to be too expensive anyway.

Why do you need the specs on the pump?

 

[cwlo]

Two points: The starter looks like the contacts can handle the load, but the lower part of it is where the heaters seem to be. (heaters are like a fuse, and protect the motor from drawing excessive amperage and burning out) either need to be adjusted (if adjustable), or replaced for the higher amp draw.

Other issue is that you may need to replace the wire to starter, and from starter to motor if its not 10 ga or so.

Chris

 

[zruvalcaba]

Two points: The starter looks like the contacts can handle the load, but the lower part of it is where the heaters seem to be. (heaters are like a fuse, and protect the motor from drawing excessive amperage and burning out) either need to be adjusted (if adjustable), or replaced for the higher amp draw.

Other issue is that you may need to replace the wire to starter, and from starter to motor if its not 10 ga or so.

Chris

Ok, I think Charles mentioned something about replacing/adjusting the heaters.

I'm running 10 ga wire from the breaker through the wall now so I don't have a problem replacing the wire...got plenty of it.

 

[camarotoolman]

Being a very cheap ***, i bought a lower horse power motor at a yard sale and put it on my 5 hp compresor with a little bigger pulley. works great, just as before. I would do a"wanted to buy " on craigs first, them ebay. 15.00 is better than 300.00. I dout you will be able to sell the 3 phase, like you no one wants one, dut They do have coper in them, worth some mpney. good hunting, ben there done that.

 

[All Systemz]

How much lower hp did you go?
I've heard of someone else that did that and it worked also.
Yes the old 3 ph motor's are worth scrap money, I listed mine on Craigslist two weeks ago for $20.00 and still no interest.

 

[zruvalcaba]

Quick and final update. Shortly after my last post, I had an offer on my Craigs List ad for the compressor. It has been sold. I went ahead and ordered the same compressor with a single phase motor directly from Northern Tool and expect it to arrive in a couple of weeks. I plan on taking IR's recommendation of installing a 60 amp breaker and running 8 gauge wire through the wall. Thanks to everyone for your comments....I certainly learned a lot from the thread. I look forward to more posts in other threads...this is a great community of enthusiasts.

PS, any recommendations for an On/Off (disconnect I think they're called?) for this compressor? Maybe something that I can run between the breaker and the motor that has either a lever or push buttons for on and off?

Zak

 

[1931S/X]

damn they recomend a 60 amp service? i have an 80 gallon t30, i bought it for 200 with no motor or pressure switch, they also robbed the copper lines. i just set it up with a baldor motor and seimens starter i bought for another compressor years ago, but never used, and a pres switch i had. thing makes a ton of air, it has a brand new motor and starter and even with the cost of them it still less than i would have paid for a working used one. the only thing i had the 3450 motor instead of 1725, but i was able to correct it with the proper size pulley.

 

[Lhorn]

If you do a search on here, there's enough info to answer all of your questions. I did the same conversion. Got a good deal on an 80 gallon Speedaire with a 5 hp 3 phase motor. I got an Ebay Baldor motor (I think a 184T). I forgot the seller, but it's pretty easy to find one. They were the biggest seller of these motors. Arrived well packed and looked factory perfect.

Replaced the motor. Used the same Sqaure D mag starter. If I recall switching to use for single phase required only 1 heater instead of 3 for 3 phase. It's a different heater - YOU CAN'T USE THE HEATERS THAT WERE IN IT FOR 3 PHASE USE. I think I figured out which heater to get from Square D's website.

I went to HD and got some thicker gauge wire to upgrade a bit of the wiring. I wanted mine to be plug in so I could use the same outlet that I use for my 220 welder (with appropriate amp breaker of course). It's worked great for me.

There are a few threads that contain pictures on this conversion, wiring etc.

 

[1931S/X]

i threw a plug on mine too. i actually wired everything on mine with old #10 extension cord. i also put a switch in it. 30 amp double pole, something along those lines.

 

[PT Doc]

Get a leviton ms602. On amazon it was less than 40 bucks. Mount out on a stee 4" box with the correct switch plate and you have a very clean setup. Other options have hinged covers that need to be opened and when they are form you don't know the status of the switch.