Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

What else do I need to set up 3 phase motor?

  • Please log in to reply
17 replies to this topic

#1 pacificdiver

pacificdiver

    Vostok 1

  • *****
  • topic starter
  • Posts: 104
  • Joined: 08 Dec 2017
  • Loc: Michigan

Posted 12 December 2018 - 03:23 PM

I'm in the process of setting up a turntable, with eventual plans to add an overarm.  My main question is how to connect my power source (hopefully my wall's 110 outlet) to the speed control.  I'm going with a 3 phase 1/2HP 1725 rpm AC motor, and a 30:1 gear box.  For control, I've seen some pretty cool programmable units, but they seem like overkill for me right now.  My question is, am I able to use a simple dial control, like this one?  

 

Speed control: https://www.grainger...m_vc=IDPPLARECS

 

If so, how do I connect the the whole setup to a power source?  I'd like to plug into standard wall outlet, but I have no idea how to interface the wall to the controller.  Can someone point me in the right direction here?  

 

Thanks in advance. 

 

 



#2 cmooney91

cmooney91

    Vostok 1

  • -----
  • Posts: 108
  • Joined: 18 Sep 2017
  • Loc: Massachusetts

Posted 12 December 2018 - 03:46 PM

No, you will need a "variable frequency drive" or an  "Inverter drive" in order to convert 110V single phase to 3phase. They can be had for about $100 on ebay. They offer excellent speed control, low speed torque and efficiency.

 

It is a common problem with old machines that hobby machinist buy, check out home shop machinist forums for "variable frequency drive" Info.

 

Most drives kick up the voltage to 240-380V with enough current to kill you instantly, so do your homework, and don't skimp out on workmanship.


  • steveastrouk and pacificdiver like this

#3 mashirts

mashirts

    Ranger 4

  • *****
  • Posts: 382
  • Joined: 18 Sep 2014
  • Loc: Elgin, TX

Posted 12 December 2018 - 04:09 PM

Why not scavenge a treadmill for good sized motor and speed control as well?   You can even find those working fine for free on craigslist. 


  • cmooney91 and pacificdiver like this

#4 dmcnally

dmcnally

    Machined Parts

  • *****
  • Vendors
  • Posts: 847
  • Joined: 16 Mar 2012
  • Loc: Lompoc, CA

Posted 12 December 2018 - 04:29 PM

Why not scavenge a treadmill for good sized motor and speed control as well?   You can even find those working fine for free on craigslist. 

+1

 

I have a VFD (220v single phase input, 220v 3 phase output) for my lathe.  It has a 2hp motor, but that's way more than you need.  A scavanged treadmill is great source for the motor and speed control.  As a bonus,  you can reuse the steel tube frame too.

 

Clear Skies,

Dave


  • cmooney91 and pacificdiver like this

#5 pacificdiver

pacificdiver

    Vostok 1

  • *****
  • topic starter
  • Posts: 104
  • Joined: 08 Dec 2017
  • Loc: Michigan

Posted 12 December 2018 - 06:23 PM

+1

 

I have a VFD (220v single phase input, 220v 3 phase output) for my lathe.  It has a 2hp motor, but that's way more than you need.  A scavanged treadmill is great source for the motor and speed control.  As a bonus,  you can reuse the steel tube frame too.

 

Clear Skies,

Dave

At the risk of sounding lazy, I'd rather just order it off of a reliable website and get new parts with warranties - less to worry about that way.  Would this be a logical setup?   From what I can tell, it takes standard 110 and steps up to 220, taking single phase from the wall and converting to 3 phase out to the motor.  I'm definitely wading through some pretty thick forest here, since I have no idea what a "phase" even is, so I'll probably have an electrician wire this thing up. I'd rather not melt my socks to my feet with a wiring mishap and end up on with a Darwin Award.  

 

Thanks in advance for any advice.  

 

Motor: https://www.automati...aiabegjj3_d_bwe

 

VFD:  https://www.automati...asabegjbo_d_bwe

 

Gearbox: https://www.mrosuppl...dwide-electric/


Edited by pacificdiver, 12 December 2018 - 06:44 PM.


#6 555aaa

555aaa

    Vendor (Xerxes Scientific)

  • *****
  • Vendors
  • Posts: 1323
  • Joined: 09 Aug 2016
  • Loc: Lynnwood, WA, USA

Posted 12 December 2018 - 07:05 PM

A brushed 12v DC motor (Leeson) might be a lot safer if you are new to big electric motors and they have great stall torque whereas an induction motor has no or nearly no stall torque which is why they are hard to start esp on a large inertial load like a glass working turntable. An industrial servo motor would be ideal but pricey. Also I don't know if you mean a three phase induction motor or a three phase brushless DC motor.

Edited by 555aaa, 12 December 2018 - 08:22 PM.

  • Jon Isaacs and pacificdiver like this

#7 dmcnally

dmcnally

    Machined Parts

  • *****
  • Vendors
  • Posts: 847
  • Joined: 16 Mar 2012
  • Loc: Lompoc, CA

Posted 12 December 2018 - 07:26 PM

At the risk of sounding lazy, I'd rather just order it off of a reliable website and get new parts with warranties - less to worry about that way.  Would this be a logical setup?   From what I can tell, it takes standard 110 and steps up to 220, taking single phase from the wall and converting to 3 phase out to the motor.  I'm definitely wading through some pretty thick forest here, since I have no idea what a "phase" even is, so I'll probably have an electrician wire this thing up. I'd rather not melt my socks to my feet with a wiring mishap and end up on with a Darwin Award.  

Dirty Harry said "A man has got to know his limitations."  It sounds like you're trying to stay within yours.

 

Good luck and Happy Holidays,

Dave

 


  • cmooney91 and pacificdiver like this

#8 bvillebob

bvillebob

    Viking 1

  • *****
  • Posts: 699
  • Joined: 19 Jan 2014
  • Loc: Eugene, Oregon

Posted 12 December 2018 - 09:15 PM

The unit you link to says the output is 1-phase, so it won't work.  You need 1 phase in and 3 phase out if you're using a 3 phase motor.  Also you probably don't want a unit that's just barely big enough to run your motor, for a 1/2 or 3/4 hp motor you'd be best off with a 1 hp VFD.

 

Sounds like you need to do a fair bit of research so you really understand what you're undertaking before making some expensive mistakes.  Just plugging stuff together only works if you have the right stuff and you know how it goes together.


Edited by bvillebob, 12 December 2018 - 09:16 PM.

  • pacificdiver likes this

#9 laixiaolue

laixiaolue

    Vostok 1

  • *****
  • Posts: 107
  • Joined: 25 Mar 2017
  • Loc: San Jose, CA, USA

Posted 12 December 2018 - 10:01 PM

I'm in the process of setting up a turntable, with eventual plans to add an overarm.  My main question is how to connect my power source (hopefully my wall's 110 outlet) to the speed control.  I'm going with a 3 phase 1/2HP 1725 rpm AC motor, and a 30:1 gear box.  For control, I've seen some pretty cool programmable units, but they seem like overkill for me right now.  My question is, am I able to use a simple dial control, like this one?  

 

Speed control: https://www.grainger...m_vc=IDPPLARECS

 

If so, how do I connect the the whole setup to a power source?  I'd like to plug into standard wall outlet, but I have no idea how to interface the wall to the controller.  Can someone point me in the right direction here?  

 

Thanks in advance. 

You need to check the voltage of your motor first. Most 3 phase motors use 220-240v. If it is a 220v motor, you need a 220v input VFD, and you also need a power transformer to convert your 110v outlet to 220v. The transformer and VFD are cheap on eBay. I use a 5KW power transformer and a 3HP VFD to drive my 2HP CNC spindle, the total cost for the power transformer and the VFD is less than 200$.

 

Those cheap VFDs are all from China, they are pre-configued to run on 50Hz. You may need to change the setting to 60Hz. The setting is kind of tricky, you may end up burn your motor if you don't set it right.


  • pacificdiver likes this

#10 dogbiscuit

dogbiscuit

    Messenger

  • -----
  • Posts: 442
  • Joined: 18 Oct 2018

Posted 12 December 2018 - 10:02 PM

On the treadmill theme.

I took the motor and control for my wife's tread mill and put it on the turn table drive of the grinding/polishing machine.

Sized the reduction so that treadmill controller indicated mph speed is table rpm.  Range is .5 to 8 rpm in tenths.  Really nice.

Got my wife a new treadmill.  I need another one for the stroke. Pulleys and old ford 3 speed and reverse transmission for now.


Edited by dogbiscuit, 12 December 2018 - 10:04 PM.

  • dmcnally and pacificdiver like this

#11 gregj888

gregj888

    Vanguard

  • -----
  • Posts: 2207
  • Joined: 26 Mar 2006
  • Loc: Oregon

Posted 12 December 2018 - 11:53 PM

There are VFDs that take 120 vac in and give 220 vac 3 phase out, no need for a transformer.

 

 https://dealerselect...10-101-H1-N.asp

 

I've had an earlier model on my lathe for about 5 years...  Really smoothed the old atlas out compared to the single phase unit.

 

Would be great on a mirror machine, but so would the treadmill motor.


  • cmooney91 and pacificdiver like this

#12 Bob4BVM

Bob4BVM

    Surveyor 1

  • *****
  • Posts: 1864
  • Joined: 23 Mar 2015
  • Loc: W. Oregon

Posted 13 December 2018 - 12:19 AM

As one who spent the last 30+ years of his working life in the industrial automation sector, the last 15 working for the world's two largest VFD manfacturers, I will offer a few Q&A:

 

How did you arrive at the 3-ph motor choice ?  First rule is you should choose a motor to match your power source. Plenty of 1-phase, 115Vac, 1/2 hp motors available

 

Bringing the 3-ph motor into the picture complicates your task immensely 

 

If you apply a VFD, it needs to match your power source & motor voltage.  I would give snot for any of the 'voltage doubler' drives on the market

 

Can a VFD create 3-ph out from 1-ph in ?  Yes it can but you'll only be using 1/3 of the input bridge; therefore you need to get a drive rated at 2X your motor HP in order to not fry the drive.

 

Get an electrician to hook it all up ?  Be careful, the average electrician who wires houses etc is as likely to blow it all up as you are. No offense to anyone, but controls stuff like a VFD is just not part of their regular MO... (ask me how I know that ! )

You need to seek out an electrician who does industrial-controls type work, and then one who has some drive experience as well. If you have any large industrial plants in your area, stop in and talk to the guy who runs the electrical dept, he can help direct you to the right resources

 

I could go on and on but I hope you get the gist of it.

 

Ideally, save yourself a lot of heartache and get a  1-phase 1/2 hp motor.  BTW, Single-phase motors do not lend themselves to speed control as does a 3-ph motor.  So if you feel you need speed control, take the advice of the folks above who recommended a DC motor.  There are small 12Vdc gearmotors that will work very well for your purpose, and you won't be dealing with EXTREMELY LETHAL voltage levels as you would with a VFD. 

 

CS

Bob

 


  • Jon Isaacs, gregj888, jtsenghas and 2 others like this

#13 pacificdiver

pacificdiver

    Vostok 1

  • *****
  • topic starter
  • Posts: 104
  • Joined: 08 Dec 2017
  • Loc: Michigan

Posted 13 December 2018 - 12:19 AM

Thanks to all who have chimed in.  I'm liking the idea of the 12 V DC motor, and it sounds like several people agree on that.  I'm thinking the lower possibility of death is definitely a plus for that choice. I think I'm going to do some light reading on this subject, as it is A LOT more complicated than I initially thought.  

 

Thanks again to all who contributed - much appreciated! 

 


Edited by pacificdiver, 13 December 2018 - 12:24 AM.

  • cmooney91 likes this

#14 Oberon

Oberon

    Mercury-Atlas

  • -----
  • Posts: 2862
  • Joined: 24 Feb 2013
  • Loc: Hunter Valley NSW Australia

Posted 13 December 2018 - 04:08 PM

At the risk of sounding lazy, I'd rather just order it off of a reliable website and get new parts with warranties - less to worry about that way.  Would this be a logical setup?   From what I can tell, it takes standard 110 and steps up to 220, taking single phase from the wall and converting to 3 phase out to the motor.  I'm definitely wading through some pretty thick forest here, since I have no idea what a "phase" even is, so I'll probably have an electrician wire this thing up. I'd rather not melt my socks to my feet with a wiring mishap and end up on with a Darwin Award.  

 

Thanks in advance for any advice.  

 

Motor: https://www.automati...aiabegjj3_d_bwe

 

VFD:  https://www.automati...asabegjbo_d_bwe

 

Gearbox: https://www.mrosuppl...dwide-electric/

These choices will work together well, and are exactly the way I would approach it. OTOH I am licenced and know exactly what I am doing when it comes to wiring, configuration, electrical safety etc. And you will need to spend more on stuff like a properly rated ventilated electrical enclosure for the VFD, start/stop buttons etc.

 

So you idea is good, but it is the execution of your idea that matters most. Absolutely recommend you pay the right person to do the job, you are working with lethal voltages and a single error could kill someone.


  • pacificdiver likes this

#15 MitchAlsup

MitchAlsup

    Soyuz

  • -----
  • Posts: 3794
  • Joined: 31 Aug 2009

Posted 13 December 2018 - 04:22 PM

A 1-phase induction motor has 3 phases on the coils. 

phase 1 gets wired to Wall+

phase 2 gets wired to Wall- 

phase 3 is generated by a 90º phase shift through a run capacitor

.....in motors over 1HP you may also find a start capacitor

 

Thus in phase the 3 poles are

+180

-180

+90 for forward rotation (or -90 for backwards rotation.)

 

If you "do the math" these motors run at 83% of current efficiency.

 

A real 3-phase motor has +120, -120, and +/- 240 and runs at 100% current efficiency.

 

There are 1-phase to 3-phase converters of capacitors, inductors, electronic, and mechanical.

One can even hook up a 1 phase motor to generate 3-phases (for another 3-phase application).

 

The only thing that makes 3-phase hard is that you are working with enough power to pull a Darwin on yourself.


  • pacificdiver likes this

#16 don clement

don clement

    Vendor (Clement Focuser)

  • -----
  • Vendors
  • Posts: 1593
  • Joined: 02 Feb 2011
  • Loc: Running Springs, California

Posted 13 December 2018 - 11:31 PM

I built a DIY rotating phase converter that generates  true 220V 3ph  from 220V single phase using a 5 hp 3 phase idler motor to power the 3 hp 3 phase motor on my Graziano SAG12  lathe. Can't vary the speed as with a VFD but then the Graziano has an excellent transmission that uses electromagnetic clutches for instant on the fly speed changes so VFD wasn't really needed. Also instant spindle stop at the push of a button on the transmission speed change  joy stick. 

 

Don


  • pacificdiver likes this

#17 Bob4BVM

Bob4BVM

    Surveyor 1

  • *****
  • Posts: 1864
  • Joined: 23 Mar 2015
  • Loc: W. Oregon

Posted 14 December 2018 - 12:58 AM

A 1-phase induction motor has 3 phases on the coils. 

phase 1 gets wired to Wall+

phase 2 gets wired to Wall- 

phase 3 is generated by a 90º phase shift through a run capacitor

.....in motors over 1HP you may also find a start capacitor

 

Thus in phase the 3 poles are

+180

-180

+90 for forward rotation (or -90 for backwards rotation.)

 

If you "do the math" these motors run at 83% of current efficiency.

 

A real 3-phase motor has +120, -120, and +/- 240 and runs at 100% current efficiency.

 

There are 1-phase to 3-phase converters of capacitors, inductors, electronic, and mechanical.

One can even hook up a 1 phase motor to generate 3-phases (for another 3-phase application).

 

The only thing that makes 3-phase hard is that you are working with enough power to pull a Darwin on yourself.

most of that's news to me :)

CS

Bob


  • gregj888 and pacificdiver like this

#18 pacificdiver

pacificdiver

    Vostok 1

  • *****
  • topic starter
  • Posts: 104
  • Joined: 08 Dec 2017
  • Loc: Michigan

Posted 14 December 2018 - 07:50 AM

These choices will work together well, and are exactly the way I would approach it. OTOH I am licenced and know exactly what I am doing when it comes to wiring, configuration, electrical safety etc. And you will need to spend more on stuff like a properly rated ventilated electrical enclosure for the VFD, start/stop buttons etc.

 

So you idea is good, but it is the execution of your idea that matters most. Absolutely recommend you pay the right person to do the job, you are working with lethal voltages and a single error could kill someone.

Thanks for the feedback on this.  The more I looked at the overall picture, the more I see I don't really need a VFD with AC setup.  I didn't realize at the outset that I'd be fiddling with 220, and I'm not ashamed to admit that 220 scares the $*%^& out of me.  I'm looking at my DC options, and it's looking like I might be able to find a 1/4 HP DC motor with speed control without killing the bank.  

 

I'm seeing the light with the treadmill motor.  Seems like a good way to get rid of the gear box as well.  Options, options!  

 

Thanks again to everyone who chimed in.  


  • dmcnally and cmooney91 like this


CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics