Help me get my compressor working please

[JohnJL]

Hi guys,

I picked up this compressor today for $300, the tank is in great condition, the 3-cylinder pump is new and pumps air when spun. The motor is a 5-hp Leeson however it isnt working properly. I am sure this is operator/installation error so your help is much appreciated...

I have 220v household single phase connected to the main armored cable from the leeson motor.

There is a second small box with a copper tube connected to the tank and a regular 120v black-white-ground cable. I connected this to switched household voltage. I am guessing this some kind of regulator? It isnt connected to the main motor in any way, at least not when I got it and the connections aren't apparent to me.

The motor makes a "buzzing" noise and if given a spin-start by hand it moves a little bit.

I just noticed while posting the pics the motor tag says Phase: "3" so for starters I am guessing I need to install a phase converter from my single-phase 220v service?

Do I also need a "magnetic starter?"

Thanks for your help!

 

[OccupantRJ]

You will need a phase converter, VFD, or a replacement single phase motor. Sorry.

 

[KrisKustomPaint]

The little box with the copper tube running to it is the pressure switch. It turns the motor on and off at set pressures. It should be wired to the motor. Sounds like your a bit in over your head. Get someone more familiar with electricity before you burn something up.

 

[OccupantRJ]

Read this also.

http://wiki.owwm.com/Default.aspx?Page=Motor Starter Wiring Diagrams&AspxAutoDetectCookieSupport=1

 

[jimp]

As RJ said, your name plate shows it is a 3 ph motor. Not going to run on single phase power.

Sorry

 

[scott37300]

Please uhook that and do some homework before you get seriously hurt! If you don't know the difference between single and three phase you really shouldn't be trying to hook this up. Size of wire, breaker, disconnects, etc all need to be addressed before bad things happen. I am not trying to be a jerk, just think you need to do more homework before trying to play with electricity. You are playing with a pretty high danger here and when you blindly hook single phase up to three phase it can lead to bad things. It sounds like you don't have much electrical knowledge, please do some learning instead of just throwing wires together when you don't understand the difference between things.

Just looking out for your safety! I'm sure you can do it with a little help but please don't do anymore guessing of wiring.

 

[JohnJL]

Sounds like your a bit in over your head. Get someone more familiar with electricity before you burn something up.

I am definately in over my head, but with some help I think I can do it...or at least have an intelligent conversation with the electrician. I did learn to rebuild motors on a site like this so with some help from generous, smart guys (like yourself, thanks for the note on the regulator!) I can make some progress

 

[JohnJL]

Please uhook that and do some homework before you get seriously hurt! If you don't know the difference between single and three phase you really shouldn't be trying to hook this up. Size of wire, breaker, disconnects, etc all need to be addressed before bad things happen. I am not trying to be a jerk, just think you need to do more homework before trying to play with electricity. You are playing with a pretty high danger here and when you blindly hook single phase up to three phase it can lead to bad things. It sounds like you don't have much electrical knowledge, please do some learning instead of just throwing wires together when you don't understand the difference between things.

Just looking out for your safety! I'm sure you can do it with a little help but please don't do anymore guessing of wiring.

Yeah, I give up playing until I get some more help here or elsewhere. The initial hook-up was with the seller...he got it in part payment for some work, it was running at the site he got it from but he didnt know how to hook it up either...the fact it didnt start working right away helped negotiate the price...

Thanks for your guys' expressions of care, I'm not playing anymore until I learn some more. Thanks for the links!

 

[KrisKustomPaint]

he didnt know how to hook it up either...the fact it didnt start working right away helped negotiate the price...

I've gotten some pretty killer deals with that strategy.

 

[e-tek]

Please uhook that and do some homework before you get seriously hurt! If you don't know the difference between single and three phase you really shouldn't be trying to hook this up. Size of wire, breaker, disconnects, etc all need to be addressed before bad things happen. I am not trying to be a jerk, just think you need to do more homework before trying to play with electricity. You are playing with a pretty high danger here and when you blindly hook single phase up to three phase it can lead to bad things. It sounds like you don't have much electrical knowledge, please do some learning instead of just throwing wires together when you don't understand the difference between things.

Just looking out for your safety! I'm sure you can do it with a little help but please don't do anymore guessing of wiring.

Well said. I really like how the tone of this site has changed for the better over the years. Seems like all the "in-your'face" types have moved on....

 

[larry_g]

You have some options here. One not mentioned is changing out the motor for a single phase motor. I would suggest that you try and get the specs on the pump head if you can. This will let you know if you can run the pump at a slower speed with a lower HP motor. Your system as it stands looks to be driving the pump quite fast, also another reason to confirm what the mfg recomends for pump speed. It is common to change the pulley sizes to allow the same pump head to be used on different HP motors but there are limits to the speed range. Know your pump head specs and then let that drive what motor and speed requirements you have.

If you choose to go with a phase converter be aware that compressors are a bit special in that they are a hard starting system that requires a lot of current to get them up to speed and not all phase converters can do this.

lg
no neat sig line

 

[GeorgiaHybrid]

Have your electrician replace the motor with a single phase like this Baldor (or equal):

http://www.electricmotorwholesale.c...catalog.prodInfo&productID=602&categoryID=103

While he is there, have him add a magnetic starter (with the correct heaters installed), run the correct sized wiring to your load center, put the right breakers in and add a cutoff near the compressor itself.

Cheap is nice but safety comes first. If the engine you learned build from a site like quits, you are out a motor. If you screw this up and start a fire, you can lose your home or worse.

 

[Skin]

go out and pick up a new single phase 220/230 motor in the 3-5hp range [yes a quality 3hp motor will work fine] that puts out 1740RPM or around there [+/- 40]. Make sure the shaft size is the same so you can re-use your motor pulley. Swap the components. Use 12 guage wire for ~20Amps, and 10 guage for ~30. If your outlet is already hooked up you do not need an electrician. Its just a matter of finding where the wires go and hooking them up between the motor and switch.

Do not mess with a phase converter. Its not worth it comparative to the cost of a motor replacement and would be far more trouble than its worth. You will also not need a magnetic starter. Do not start messing with pulley sizes either. 1740 is about as slow as any motor will spin and that pulley is already huge compared to the pump.

The only thing i would do is move the motor in and purchase a substantially shorter belt. Just a guess but the one thats on there doesnt look factory installed.

 

[JohnJL]

So after some homework....ahem...I've unhooked and cleaned up everything.

I love that matched leeson motor and it looks like an absolute hoss...not sure I want to go through doing a phase converter, etc.

I also researched the DV-40 pump, its a new devilbiss 40. Rated for 13 ft3 at 120 psi at 1375 rpm. 1375 is what the leeson motor was rated at 220v 3-phase so with the pulley ratios the pump was running ~150% faster, or about 2000 rpm.

I use the compressor for shotblasting small parts, air files, grinders, impact guns and drills. It runs on the weekend only and maybe only 2 hours total per day but during those times (like everyone) I hate running out of air.

So lets go down two roads...1st is keeping the existing motor and regulator. 2nd is replacing the existing motor with a 1 phase replacement.

With keeping the existing motor, I am assuming the existing regulator is good. The chart on the side reads it is rated for 5hp at 3-phase 220v. That same chart reads 3 hp for 1-phase 220v. So I guess it only works for me if I keep this motor (or a 3-hp 1-phase)

With this existing motor I believe I need a. a phase converter, 2. a magnetic motor starter for the motor and an integrated switch to also power the regulator as well as allow the regulator to turn on/off the motor as needed.

If I replace it with a 1-phase motor I dispense with the need for a converter, and I either need to keep the new motor under 3 hp, or upgrade the regulator. Lets say I go for a 5hp baldor or similar. Baldor says I still dont need a starter motor in its spec page for that motor. So I really only need a new regulator, and an integrated switch to allow the regulator control over the start/stop of the main motor.

RJ and Georgia, those links were very helpful, thanks.

 

[Skin]

erm, your motor speed is 1740RPM, the pump pulley is substantially larger than the motor pulley. What math did you use to arrive at an RPM that exceeds the capabilities of the motor?

And its not a regulator its a pressure switch. They're rather inexpensive so replacement isnt the end of the world. Thats all you need to replace to get the compressor to start and stop. A phase converter is a whole nother ball game and makes zero sense in your application since it overcomplicates the situation greatly and blows by the cost of a replacement motor. It makes no sense to purchase a $1000 phase converter if you can just replace the motor for a few hundred.

 

[GeorgiaHybrid]

You can run a single phase 5 HP motor without a problem as that compressor won't know if the motor is 3 phase or single phase. You can use the pressure switch to start the motor (if you replace it with one rated for 25 to 30 amps) but running 23+ amps thru it will shorten its life.

By using a magnetic starter, you only run a 115 circuit thru the switch that will energize the mag starter to allow full 230 voltage to go to the motor and that will allow your existing switch to be used with a 5 HP motor. I didn't check the specs on the Baldor that I linked to but if it has a reset button, you don't "need" the mag starter.

If you do use one though, the overloads are built in by using the correct heater for your motor. A 5 HP motor is the breaking point for using/not using a mag starter. Everyone has an opinion about them but I'm from the safer than sorry school and tend to "overbuild" most of my projects.

Edit: You do not need to change out your pressure switch if you use a mag starter with a 5 HP motor as it is only used to energize it.

 

[99camaro]

I picked up a speedaire 80 gal 5 hp 3phase compressor cheap from a local site . What I did was build a Rotary Phase Converter for mine. I found a site ( google "rotary phase converter" ) that has a schematic and material list for building one . Alot of the materials needed can be found in your local metal scrap yards . If you have a understanding of the sequence of operations and are comfortable working with electric , it is not hard to do . I have less than 100 dollars total invested in mine to build it . The hardest part I found was balancing the 3 phases of power ,but even that is not all that bad .
If you are not sure you are able to build one ,you can buy one .

If you are going to just change the electric motor for a single phase one ,get a 5 hp motor . You also will need to know what the working rpm of compressor is. This is needed so you do not over spin compressor and can install the correct pulley on the new motor .

 

[JohnJL]

I picked up a speedaire 80 gal 5 hp 3phase compressor cheap from a local site . What I did was build a Rotary Phase Converter for mine. I found a site ( google "rotary phase converter" ) that has a schematic and material list for building one . Alot of the materials needed can be found in your local metal scrap yards . If you have a understanding of the sequence of operations and are comfortable working with electric , it is not hard to do . I have less than 100 dollars total invested in mine to build it . The hardest part I found was balancing the 3 phases of power ,but even that is not all that bad .
If you are not sure you are able to build one ,you can buy one .

If you are going to just change the electric motor for a single phase one ,get a 5 hp motor . You also will need to know what the working rpm of compressor is. This is needed so you do not over spin compressor and can install the correct pulley on the new motor .

Thanks, I admire your abilities. I have 1000 other jobs to get done including getting the track car ready for the season so I cant get to quite that level of kluging.



After some more investigation I am looking for a 1-phase 5hp motor with the same shaft diameter so I can reuse the pulley. That would be 1750rpm.

So some more questions for your respectful consideration and assistance:

1. I've researched a bunch of Baldor and Leeson motors, the price rance is $200-1400...

2. With the above range and limited knowledge, I'd appreciate comment on my conclusion that I am best served with a capacitor-start 5hp 1-phase motor. With that I can re-use mine or install an adjustable pressure switch between the home power supply (20 amp 220V) and the motor hot supply. If the pressure switch is sensing pressure below the lower limit it will close and power start-up and running of the pump. I'd also wire in a "total off" switch when the shop is not is use.

3. If not using a capacitor-start motor then I will need a magnetic starter. My personal preference is a separate unit but I may be misguided on this. I have found it easier to diagnose parts and replace them with separate units than from integrated units however happy to be corrected on this.

4. I havent been successful in finding stats on the max RPM and pumping capacity of the devilbiss DV-40 pump. This is what is on my unit now and I want to re-use this as it is new and comparing to similar unitson the Devilbiss site this should suit my needs. I'd like to confirm that though, especially in confirming the required RPM of the pump, what pulley size I need, and if I can be opportunistic and grab a deal for a 3750 rpm pump.

Thanks guys and gals.

John

Appreciate your

 

[Charles (in GA)]

You have a 1740 RPM motor now, if it worked properly, all you need is a 1740 or so RPM motor in single phase of the same horsepower.

Pressure switches generally will not handle the amperage of a real, full 5 hp motor. When they get this big, the pressure switch is usually connected to a motor starter and the starter makes the connection between the power and the motor. Pressure switch contacts will overheat and burn up with this kind of amperage going thru it. Also, if your 5 hp single phase motor does not have internal thermal protection (as evidenced by a reset button on the end of the motor) that is another reason for needing a motor starter, as they have "heaters" in them that act as the thermal overload for the motor (you have to select the correct heating element from a large list of them, to make this work properly.

Charles

 

[W-Cummins]

After some more investigation I am looking for a 1-phase 5hp motor with the same shaft diameter so I can reuse the pulley. That would be 1750rpm.


2. With the above range and limited knowledge, I'd appreciate comment on my conclusion that I am best served with a capacitor-start 5hp 1-phase motor. With that I can re-use mine or install an adjustable pressure switch between the home power supply (20 amp 220V) and the motor hot supply. If the pressure switch is sensing pressure below the lower limit it will close and power start-up and running of the pump. I'd also wire in a "total off" switch when the shop is not is use.

A real 5hp motor will not run properly on a 240v 20 amp supply it needs a 30amp min... I too would not run a 5hp motor with out a mag starter. BTW you want one with a 230V coil so you don't need to have 120v at the compressor.

William....

 

[ZRX61]

at least have an intelligent conversation with the electrician.

Man, that's some low hanging fruit right there... but I'll say no more in case I need to ask an electrical question sometime

 

[cnc-me]

Get a 3HP Single phase motor
Slow the pump down with a smaller pulley on the motor,
so it lasts longer than a year.
Pressure switch is ok, but a magnetic starter with the correct
"heaters" would protect your new motor much better.
You can put a clamp type amp meter on the motor, if its at FL amps or below
you are good.

 

[kams1973]

My original post was wrong. I looked up the pump and found the following specs.

5HP
PUMP: DEV-40 (1 stage 3 cylinder)
RPM: 1220
CFM Displacement: 21
CFM Delivery: 13
PSI: 125

http://www.centrair.ca/piston.html#SDI (half way down the page)
http://www.centrair.ca/partsbreakdown/sdi_pumps.pdf
http://www.centrair.ca/manuals/SDI_Manual.pdf

 

[JohnJL]

I've heard from Leeson, their replacement 1-phase has "start/stop capacitator" (his words) but no starter. I asked the rep for clarification on their recommendation and specifications.

I also found a few Baldor 1430T (5 hp, 184 frame, 1 1/8 shaft single phase 1750 rpm) units on ebay and bid on one...

I looked at my panel again, here's a pic. I told the electricians to prepare for a "serious" compressor...does this indicate a 40 Amp or 80 Amp circuit ?!?!?!

 

[Lhorn]

I think I bought one of those same Baldor motors off of Ebay. I forgot the name of the company but they sell a lot of motors on Ebay. Mine showed up well packed and looked to be in brand new condition. With the help of the guys on this site, I, as a novice converted my 3 phase Speedaire to single phase. Other than the new motor, I upgraded some of the wiring, put a big switch on it so I can turn it off at night and changed the heater in the mag starter to the appropriate one for the single phase. I believe mine is running on a 30 amp breaker than I had put in a few years ago for my Miller 175 welder. I don't work it too hard....die grinders a DA once in a while and it's never tripped the breaker.

 

[JohnJL]

LHorn, I am going the same route, won en eBay auction for one of these:

http://www.baldor.com/products/deta...=1400-1800&winding=36WGT077&rating=40CMB-CONT

Catalog Number: L1430T
Description: 5HP,1725RPM,1PH,60HZ,184T,3634LC,ODTF,F1
Ship Weight: 79 lbs.
List Price: $778

Paid less than half retail, hope its in good condition...

 

[hllon4whls]

I looked at my panel again, here's a pic. I told the electricians to prepare for a "serious" compressor...does this indicate a 40 Amp or 80 Amp circuit ?!?!?!

forty.

 

[Lhorn]

To clarify, since you haven't had it done yet, I agree, go with at least 40 amp. I was only saying that so far mine works on a 30 amp, not that I recommend you get a 30 amp since the price difference between the two would likely be very modest.

hope its in good condition...

If it's like mine, you will be very happy. They don't say where the motors come from but my guess is that take them off brand new machinery to put on a different (perhaps 3 phase?) motor. I looked mine over with a fine tooth comb and there is literally zero evidence that it's ever been used.

 

[OccupantRJ]

LHorn, I am going the same route, won en eBay auction for one of these:

http://www.baldor.com/products/deta...=1400-1800&winding=36WGT077&rating=40CMB-CONT

Catalog Number: L1430T
Description: 5HP,1725RPM,1PH,60HZ,184T,3634LC,ODTF,F1
Ship Weight: 79 lbs.
List Price: $778

Paid less than half retail, hope its in good condition...

That capacitor can looks like a dual capacitor setup. If so, it's even better for a compressor hard starting application.

 

[JohnJL]

Appreciate some help confirming my shopping list...

I will reuse the pump, thats a new Develbiss 40. 13.5CFM @ 125psi
I will reuse the 80g tank

I have ordered a replacement motor described above. I've looked through the owners manual (http://www.baldor.com/support/literature_load.asp?ManNumber=MN400)

and the specifications and drawings make reference to capacitators however there is no statement of whether the motor has a "reset switch." The motor hasnt been delivered yet.

The existing pressure switch has seen some better days and the plate says its rated only for 3HP 1phase. So I need a pressure switch. Was looking at this one today:

http://www.princessauto.com/worksho...ponents/8050742-70-to-150-psi-pressure-switch

One problem is I havent found a switch yet rated above 3hp 1 phase. First question: Does anyone have a wiring diagram for this application where its a 208-230v 1 phase 5hp motor, pressure switch and magnetic starter.

Next question, is a magnetic starter necessary and if so could someone pls point me in the direction of a wiring diagram including the starter? I looked at this one today:
http://www.princessauto.com/worksho...econdary-components/8050783-magnetic-starters

Appreciate the help...

 

[GeorgiaHybrid]

I have that motor on my Quincy (that's the reason I linked to it). It does not have a reset button. You will need a mag starter with the right heaters (you can order that from the same place I linked to before or any other motor shop, just tell them the HP and that it is single phase) but don't worry about the pressure switch. It just uses a single leg at low amperage to kick the relay on the mag starter.

As for wiring, this is what mine looked like after hooking it up.

Note that I screwed up with the notations, the green wire is not "neutral" but should read "ground" although in this case they come from the same place (main load center).

Many thanks to Charles in Ga for his help with mine.

 

[OccupantRJ]

JohnJL, consider the pressure switch as a triggering device for the magnetic starter. When the need is for more air, the pressure switch will close it's electrical contacts and turn on the magnetic coil of the motor starter. The mag starter will then slam closed, passing power to the motor. When pressure is achieved, the pressure switch will tell the mag starter to open up or (drop out). The starter has heavy electrical contacts to handle the required amperage draw of the motor. At the base of the mag starter, there should be a heater (current overload protective device), which should be rated for the expected motor load. These heaters are coded and marked for their amp rating. I just whipped up a hand drawn sketch of a simplified hookup for 240 volt air compressor motor for you. Note that this is for a motor starter with a 120 volt control coil. A 240 volt coil is wired differently. The motor starter you selected has a 120 volt coil. A simple house light switch can be used for your on-off switch, since it is only controlling the starter's coil. Hope this helps you. I did not include the green ground wire for simplicity, since a picture had already been posted. We all have to start somewhere.

 

[JohnJL]

Thanks Georgia for the link.

That site has more technical information.

This starter looks like the right one: http://www.electricmotorwholesale.c...atalog.prodInfo&productID=2743&categoryID=316

Matched with this case:

Question about the starter options available: the catalog offers a range of "Overload FL Amp Range" options. The lowest is 4-6 and the highest is 28-36. What determines the range of the "Overload FL Amp Range" I need? Is this related to the motor amp operating range? My motor's is 22A.

 

[GeorgiaHybrid]

Just give whoever you are buying it from a call. When I bought my motor and mag starter (the Siemens that I showed above), I just told the guy to give me the correct heater for it but I will go out in a bit and check to see what rating it is.

 

[OccupantRJ]

Thanks Georgia for the link.

That site has more technical information.

This starter looks like the right one: http://www.electricmotorwholesale.c...atalog.prodInfo&productID=2743&categoryID=316

Matched with this case:

Question about the starter options available: the catalog offers a range of "Overload FL Amp Range" options. The lowest is 4-6 and the highest is 28-36. What determines the range of the "Overload FL Amp Range" I need? Is this related to the motor amp operating range? My motor's is 22A.

The starter you have linked to seems to be the electronically adjustable type, adjusted for the required amp load, versus the previous type with a fixed heater rating. You would order and set it up it to fit the required amp draw of your motor.