# exactly what do i need



## davidh (Nov 17, 2012)

to power a 2-1/2 - 3 h.p. 130 volt dc motor that includes a speed control, using 110 or 220 v single phase ?     
i saw the information somewhere but cannot put my finger on it.   

i have these two motors from a friend that were taken off treadmills. . . i would like to use them for something with control of the speed.  like my atlas 12  lathe maybe or my tool grinder or whatever.

 . . . .could someone point me to it ?

thanks in advance.

and my shaft repair came out beautiful . . . im right proud !


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## swatson144 (Nov 17, 2012)

If you are lucky you can just use the speed controller that was on the treadmill. I was that lucky just threw out the control panel and soldered a potentiometer on the speed controller board. Some of the boards have minor problems for machinery use like mine likes to be started from 0 but there is a work around that I haven't implemented since it doesn't bother me.

Steve


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## Tony Wells (Nov 17, 2012)

Build or buy?


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## davidh (Nov 17, 2012)

sorry, i should have said "buy" if affordable. . .

the motors are all i had donated. . . the rest of the treadmill disappeared.


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## Cal Haines (Nov 17, 2012)

davidh said:


> to power a 2-1/2 - 3 h.p. 130 volt dc motor that includes a speed control, using 110 or 220 v single phase ?
> i saw the information somewhere but cannot put my finger on it.
> 
> i have these two motors from a friend that were taken off treadmills. . . i would like to use them for something with control of the speed.  like my atlas 12  lathe maybe or my tool grinder or whatever.
> ...


Nice job on the shaft repair!

How big are these motors?  The 3HP DC motor on my 10EE is huge.

Something like this controller might work:
http://www.galco.com/buy/KB-Electronics/KBIC-225
However it's designed for a 180V motor.  It may be possible to voltage limit it to 130, I'm just not sure.

130VDC is an odd voltage.  To get there from 120VAC you need some kind of boost transformer.  The typical 120VAC drive puts out about 90VDC.

_Cal_


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## twstoerzinger (Nov 18, 2012)

*DC drives for 3 hp*

I'm a little confused. Is the 3 hp motor off a treadmill? Seems like a really large motor for a treadmill.

The rule of thumb for motors (either AC or DC) is that 120 VAC supply usually tops out at about 1 hp at about 16 amps.
You can get 1.5 hp at 120 vac if you have a 20 amp circuit with a slow-blow breaker, and you don't load the motor up to the full 1.5 hp.

Then you move up to 230 VAC.
The next normal motor size is 2.0 hp which typically pulls 12 amp on single phase 230 vac.
3 hp is usually around 17 amps at 230 vac.  

Here's a link to a NEC table of average full load currents for AC motors:
http://www.electricmotorshop.net/index.php?option=com_content&view=article&id=687&Itemid=352
(your mileage may vary depending on the specific motor that you have)

DC drives pull somewhat more AC currant for the same hp, since there are some losses in the DC electronics.
DC motors in the 2 - 3 hp size usually have a separate circuit for the field. The DC drive furnishes both the field and the armature current.
The DC drive will have some means of adjusting the field current to match that of the motor nameplate.
DC motors smaller than 1 hp often have permanent magnets for the field instead of an electro-magnet. In this case, you just don't use the field terminals on the drive.

Is there a nameplate on the motor that you could photo and post?
Terry S


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## davidh (Nov 18, 2012)

*Re: DC drives for 3 hp*

[QUOTE

Is there a nameplate on the motor that you could photo and post?
Terry S[/QUOTE]

two motors. .  .  the pm in the description probably means per. magnet ?


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## Tony Wells (Nov 18, 2012)

Very likely in addition to the initials of the company, the motor is a permanent magnet motor. And 3 hp is not uncommon on the heavier treadmills. The current draw of 20 amps is an indicator. That is a pretty heavy duty motor. I had one to play with for a while, after replacing my own TM motor, and they are high torque motors, and I believe make good building block materials. I cracked one of the magnets in mine and tossed it.


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## davidh (Nov 19, 2012)

Tony Wells said:


> Very likely in addition to the initials of the company, the motor is a permanent magnet motor. And 3 hp is not uncommon on the heavier treadmills. The current draw of 20 amps is an indicator. That is a pretty heavy duty motor. I had one to play with for a while, after replacing my own TM motor, and they are high torque motors, and I believe make good building block materials. I cracked one of the magnets in mine and tossed it.


tony, are you saying they ain't worth a crap and i should just just part um out and save the magnets for the kids to play with ?    
 i do have some pretty big three phase machines that i was hoping would be an reasonably easy conversion. . .  if not, please say ?   thanks again.


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