Antique Engines and Old Iron
[Home] - [HELP] - [Forums] - [Groups] - [Classified Ads] - [Subscribe] - [Books] - [Sponsors] -

Go Back   SmokStak > SmokStak® Shop Equipment Tools and Techniques > Machine Shop and Tool Talk
Forgot Password? Join Us!

Notices

Machine Shop and Tool Talk Shop Equipment, fabrication, repairs, how to fix it, which tool to use for the job. Machinist shop talk, straight to the point.

Machine Shop and Tool Talk

3 phase conversion options


this thread has 16 replies and has been viewed 1662 times

Reply
 
Thread Tools Display Modes
  #1  
Old 12-26-2015, 06:51:28 PM
Amax Amax is offline
Subscriber
 
Join Date: Aug 2015
Location: Manchester, Vermont
Posts: 664
Thanks: 326
Thanked 362 Times in 227 Posts
Default 3 phase conversion options

I would like to get my 3 phase Bridgeport running. I am not sure of the best way to accomplish this and so I am looking for advice. Hopefully, I can get it working with what I have on hand:

Bridgeport:

1 hp
3 phase
208/220/440 volts

This machine will see light duty work. Cutter speed is controlled by pulleys. There will be no sudden reversal.

Buffer:

2 hp
3 phase
220 volts

It would be nice to be able to use this buffer, but perhaps it can also be used as a rotary converter.


Phase-a-Matic:

I have an unused Phase-a-Matic with a nominal 600 mfd capacitor inside plus an extra (not connected) nominal 300 mfd capacitor.


What options do I have? Can I use the P-a-M (with the big capacitor) to run the buffer, and then use the buffer to produce 3 legs for the mill?

Should I forget about the P-a-M and hook up a 2 hp (or bigger) single phase electric motor to spin it? (Easy to replace one buffing wheel with a pulley.) Or maybe a small gas engine?

My goal is something that will work and my preference is with minimum or no additional expense.

BTW, while it would be nice to still be able to use the buffer, that would be icing on the cake as I already have another 120 v buffer that I can use.

Thanks in advance.



Click image for larger version

Name:	IMG_2008.jpg
Views:	77
Size:	38.6 KB
ID:	242308

Click image for larger version

Name:	IMG_2010.jpg
Views:	58
Size:	61.4 KB
ID:	242309
Reply With Quote
Sponsored Links
  #2  
Old 12-26-2015, 07:44:21 PM
Nebraska Kirk Nebraska Kirk is offline
Registered-I
 
Join Date: Nov 2011
Location: Tecumseh, Nebraska
Posts: 340
Thanks: 122
Thanked 772 Times in 174 Posts
Default Re: 3 phase conversion options

When I bought my Bridgeport mill, I found it easier to just put a single phase motor on it.
Reply With Quote
The Following User Says Thank You to Nebraska Kirk For This Post:
  #3  
Old 12-26-2015, 08:30:36 PM
Amax Amax is offline
Subscriber
 
Join Date: Aug 2015
Location: Manchester, Vermont
Posts: 664
Thanks: 326
Thanked 362 Times in 227 Posts
Default Re: 3 phase conversion options

Quote:
Originally Posted by Nebraska Kirk View Post
When I bought my Bridgeport mill, I found it easier to just put a single phase motor on it.
I actually traded my original Bridgeport that had a single-phase motor mounted up top. The reason I did the swap was that my shop has a low ceiling so I need a very low-profile motor. The stock 3 phase motor has a much lower profile.
Reply With Quote
  #4  
Old 12-26-2015, 08:58:54 PM
ChipTosser ChipTosser is offline
Subscriber
 
Join Date: Mar 2011
Location: Ashley, Ohio
Posts: 234
Thanks: 122
Thanked 97 Times in 75 Posts
Default Re: 3 phase conversion options

First off, what size of motor is the phaseamatic rated for? It should be stated on the unit.
If you convert your mill to single, you are still left unable to run the buffing jack.
Reply With Quote
  #5  
Old 12-26-2015, 09:34:18 PM
Richard W. Richard W. is offline
Registered-III
 
Join Date: Nov 2004
Location: Molalla, Oregon
Posts: 733
Thanks: 922
Thanked 941 Times in 288 Posts
Default Re: 3 phase conversion options

A "Phase-A-Matic" 1 to 3 hp static converter will work fine. Also you can instant reverse with it at lower RPM for tapping. Used one for years on a Jet 2 speed Bridgeport clone.

Richard W.
Reply With Quote
  #6  
Old 12-26-2015, 10:28:09 PM
beezerbill beezerbill is offline
Subscriber
 
Join Date: Sep 2012
Location: Boulder, Colorado
Posts: 1,171
Thanks: 182
Thanked 627 Times in 422 Posts
Default Re: 3 phase conversion options

I've used the Phase A Matic in a bunch of places - kind of an install and forget item. Power will be lower but sounds like that shouldn't matter. Should work fine for the mill. Not sure if you can run both machines on one unit, though. Might be simplest if each machine had its own unit.
Reply With Quote
  #7  
Old 12-26-2015, 11:39:34 PM
Amax Amax is offline
Subscriber
 
Join Date: Aug 2015
Location: Manchester, Vermont
Posts: 664
Thanks: 326
Thanked 362 Times in 227 Posts
Default Re: 3 phase conversion options

Is a way to generate 3 phase for a smaller motor (the 1 hp on the mill) by driving the 2 hp motor on the buffer (a) by a third motor or (b) from the Phase-a-Matic?

IOW, the Phase-a-Matic runs the 2 HP buffer under no load (not buffing anything) and I grab three legs from that to run the smaller 1 HP mill?

If that works, then with the milling machine off I could use the buffer by itself.
Reply With Quote
  #8  
Old 12-26-2015, 11:58:54 PM
vdrive vdrive is offline
Registered-I
 
Join Date: Sep 2010
Location: Chicago,il
Posts: 151
Thanks: 34
Thanked 42 Times in 32 Posts
Default Re: 3 phase conversion options

I've been using the phase a matic HD (heave duty) rated at 1-3 hp. for around 10years with no problem.

I would thing you could run both machines at the same time. As long as you don't go over the combined rating of the PaM box. And you don't try to start both machines up at the same time


I just don't start them at the same time.
Reply With Quote
  #9  
Old 12-27-2015, 03:27:27 PM
dalmatiangirl61 dalmatiangirl61 is online now
Subscriber
 
Join Date: Feb 2010
Location: San Marcos, Texas / McGill, Nevada
Posts: 4,850
Thanks: 5,794
Thanked 4,151 Times in 2,051 Posts
Default Re: 3 phase conversion options

Friend uses a PaM static converter to run a 3 ph idler motor that then powers his lathe, beyond "it works", I don't know anything more. I think your plan of running the buffer to run the mill will work, but there are smarter people here than me............
__________________
Those who can see the invisible, can do the impossible
Reply With Quote
  #10  
Old 12-28-2015, 02:35:34 AM
dkamp dkamp is offline
eMail NOT Working
 
Join Date: Oct 2007
Location: LeClaire, Iowa, USA
Posts: 1,671
Thanks: 34
Thanked 882 Times in 580 Posts
Default Re: 3 phase conversion options

Your thoughts, and Kris's suggestion are correct- if you power up the buffer by the PAM, and you tie all three leads from the buffer through to the mill, it'll run... because your buffer will be acting essentially as an 'idler'.

Work yes... optimal, not, but sufficient, certainly. Make it so!
Reply With Quote
The Following User Says Thank You to dkamp For This Post:
  #11  
Old 12-29-2015, 07:52:54 PM
Amax Amax is offline
Subscriber
 
Join Date: Aug 2015
Location: Manchester, Vermont
Posts: 664
Thanks: 326
Thanked 362 Times in 227 Posts
Default Re: 3 phase conversion options

Here is an update. Based on the advice you all have provided and a quick call to Phase-a-Matic tech support, I believe that I understand how I can make this work.

Tech support confirmed that the PaM I have (with a nominal 600 mfd capacitor) is for 3 to 5 HP and too big for my 1 HP Bridgeport and 2 HP buffer, even if they were both running at the same time.

They instructed me to switch to the nominal 300 mfd capacitor I had purchased years ago. I had purchased two; one rated 240 v and the other rated 120 v. The 240 v cap is misplaced. PaM tech support said that I only need one and that the 120 v rating is not a problem, so what I have will work.

They instructed me to unsolder the big capacitor and to replace it with the smaller one and went on to say that I would be able to power my mill, the buffer or both. I have already swapped the capacitor but have not yet wired up the P-a-M.

To close the loop on some of the comments above, it seems there are two ways to hook this up. The first or 'normal' way is to wire both three-phase machines across the Phase-a-Matic output terminals. When you start a motor, a red light should illuminate and then go out.

If the red light does not go out, then you use the 'abbynormal' hookup. In this case, both three-phase motors are again connected in parallel but a toggle switch is added in the center leg between the P-a-M and the motor connections. The switch is closed to start, the red light comes on, and then you open the switch. The red light goes out - I forgot to mention that one of the two three-phase motors is therefore acting as an idler motor (as referenced in prior posts). Basically, this is for a situation where 'more' is needed than the P-a-M can provide, so it is electrically removed from the circuit after the motors start and the idler motor is supplying three-phase for the working motor.

Hopefully that is clearer than mud. I have got to wire things up 'normal' to see if it all works. Wish me luck LOL.

BTW, P-a-M seems to be the last of a dying breed. You call them up, a person answers, and that person can immediately help you. No long-winded messages, no call center BS, noone asking me to press '1' for a different language - just immediate, personal and competent advice. I think the call lasted 5 minutes. Good on them!!!!
Reply With Quote
  #12  
Old 12-29-2015, 08:23:41 PM
Pat Barrett Pat Barrett is offline
Subscriber
 
Join Date: Nov 2004
Location: Brookhaven, Mississippi, USA
Posts: 3,096
Thanks: 929
Thanked 2,007 Times in 1,168 Posts
Default Re: 3 phase conversion options

Me and the boys have ran a 3 hp milling machine and a colchester lathe, 3 hp also on a Phase A Matic for the last 5 years, and, yes, it doesn't have the power it would on 3 phase but as hobbyist, it does a good job.
Reply With Quote
  #13  
Old 12-29-2015, 08:31:56 PM
Amax Amax is offline
Subscriber
 
Join Date: Aug 2015
Location: Manchester, Vermont
Posts: 664
Thanks: 326
Thanked 362 Times in 227 Posts
Default Re: 3 phase conversion options

Quote:
Originally Posted by Pat Barrett View Post
Me and the boys have ran a 3 hp milling machine and a colchester lathe, 3 hp also on a Phase A Matic for the last 5 years, and, yes, it doesn't have the power it would on 3 phase but as hobbyist, it does a good job.
When you say less power, does that just translate to lighter cuts?
Reply With Quote
  #14  
Old 12-29-2015, 09:07:15 PM
Pat Barrett Pat Barrett is offline
Subscriber
 
Join Date: Nov 2004
Location: Brookhaven, Mississippi, USA
Posts: 3,096
Thanks: 929
Thanked 2,007 Times in 1,168 Posts
Default Re: 3 phase conversion options

Yes, you can't just hog into the work, like you could if it was on real 3 phase, but you can do hobbyist work and not production work.
Reply With Quote
The Following User Says Thank You to Pat Barrett For This Post:
  #15  
Old 12-30-2015, 08:32:27 PM
Amax Amax is offline
Subscriber
 
Join Date: Aug 2015
Location: Manchester, Vermont
Posts: 664
Thanks: 326
Thanked 362 Times in 227 Posts
Default Re: 3 phase conversion options

Today I hooked up my Phase-a-Matic and it worked.

It took me longer than it should have to do it all, but I am not a professional electrician who does this every day.

One issue is with how P-a-M puts these things together. You get a tiny junction box with a terminal strip inside, and this is where you connect all your thick and stiff copper wires. You need hands the size of a child's and the dexterity of a surgeon. Well, zero out of two ain't bad. LOL.

The good news is that I did not electrocute myself, burn anything down, or ruin any equipment in the process. So that is a win.

My milling machine starts up crisply and quickly. The red light is only on for a moment.

So far, I am a happy camper.

I was not able to try the buffer as I only had one three-phase male plug on hand. I have also not yet hooked up the table feed motor on the mill.

Thanks again for the good advise provided.

Click image for larger version

Name:	IMG_2043.JPG
Views:	50
Size:	112.8 KB
ID:	242647
Reply With Quote
The Following 2 Users Say Thank You to Amax For This Post:
  #16  
Old 01-03-2016, 09:20:37 AM
Tracy T Tracy T is offline
Subscriber
 
Join Date: May 2009
Location: Cedarbluff, Virginia, USA
Posts: 2,867
Thanks: 899
Thanked 1,499 Times in 885 Posts
Default Re: 3 phase conversion options

I had a older gentleman help me build my own converter and was able to run two 7.5hp motors at the same time, it was a two post car lift with a bad static converter with the schematic in German. The most expense was the idler motor. He liked to use a 5 HP 3600 rpm for the idler. I sold the lift some time ago and got back in touch with him and we built another last year. I didn't want his knowledge to go by the wayside he is 92! He said the higher voltage rating on capicators is basically the amount of insulation in them. Maybe I can dig mine out and post a few pictures. Mine consist of a timer(one shot), start & run capicators, and two contractors with the idler motor and that's it! I have been keeping a eye out for 5hp 3600 rpm 3 pH motors, last one was $100. One key thing on my setup is you have to be able to rewire your equipment for 220/240 volt 3 phase. His design give %100 power no derating to 2/3 power.
Reply With Quote
The Following User Says Thank You to Tracy T For This Post:
  #17  
Old 01-07-2016, 01:07:32 AM
dkamp dkamp is offline
eMail NOT Working
 
Join Date: Oct 2007
Location: LeClaire, Iowa, USA
Posts: 1,671
Thanks: 34
Thanked 882 Times in 580 Posts
Default Re: 3 phase conversion options

Yes, what Tracy refers to is just a common rotary converter. the OP's Phase-A-Matic sounds like it's a 'static' converter... basically, starting the motor by kicking it off in the right direction, then once spinning, running it on just two of the three-phases, hence the 2/3rd's power suggestion.

In very simple terms, a 'rotary' converter, is nothing more than a static converter connected to an idler motor.

SO, when you start ONE machine powered by a static converter, and let it run with no load, then connect a second machine, the first is effectively an IDLER motor, and when you load the second one, you're getting benefit of the first machine actually feeding the third leg of your loaded motor.

There's nothing really complicated about the static converter, it's just capacitors and a control relay, functionally identical to that used in any common self-starting rotary-converter design. Fitch Williams published his design notes oh... three decades or so ago, and that's what I based all my rotary converters on, and I'll admit, as many times as I could've just made a static converter, it was too easy to put an idler motor on it, to make it a full rotary...

...but now I have VFDs on darned near everything...
Reply With Quote
The Following User Says Thank You to dkamp For This Post:
Reply

Bookmarks


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

F o r u m Jump

Similar Threads Chosen at Random
Thread Thread Starter F o r u m Replies Last Post
3 Phase to Single Phase Conversion Jim McIntyre Generators & Electric Motors General Discussion 10 04-03-2011 06:58:39 AM
US Motor Div Generator Conversion To Single Phase 220V From Three Phase jimybud Generators & Electric Motors General Discussion 4 06-27-2010 08:19:50 PM
CCK phase conversion garth Onan Generators 3 10-21-2009 11:14:19 AM
3 phase motor to generator conversion? DirtbikePilot Generators & Electric Motors General Discussion 14 06-13-2008 07:58:13 AM
3-Phase to Single phase Conversion Dewey Kohler Generators 5 10-06-2005 05:54:30 PM


Use "Ctrl" mouse wheel to change screen size.
All times are GMT -4. The time now is 11:07:30 PM.

Smokstak and Enginads site search!


All use is subject to our TERMS OF SERVICE
SMOKSTAK® is a Registered Trade Mark - A Community of Antique Engine Enthusiasts
Copyright © 2000 - 2019 by Harry Matthews P.O. Box 5612 - Sarasota, FL 34277