# Wiring up an Parvalux sd21 motor HELP !!:)



## Mr blue in the dark (Apr 12, 2020)

Hi, hope you can advise, I picked up an Unimat SL lathe of ebay but needed to buy a small motor.
I Purchased a Parvalux SD21   AC single phase motor thinking i would just have to connect a live, neutral, and earth! stupid me 
It has 2 white wires, one black and an earth. Not sure how to set it up, does it need a capacitor like iv seen on other motors? (it didn't come with one),
Any general advice on wiring it up would be most appreciated!!

Thanks!!!!


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## stevehuckss396 (Apr 12, 2020)

take a picture of the name plate and post the picture. Wiring info should be on the plate


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## Mr blue in the dark (Apr 12, 2020)

hi, thanks for the reply, unfortunately there is no plate on the actual motor, the only info i have is on the box, iv attached a couple of pictures.
thanks again


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## deverett (Apr 12, 2020)

Attached is a wiring data sheet from Parvalux to help you.  The capacitor you require is 2.5Mfd.
I note that your SD21 motor has only a maximum power of 20 Watts (2800rpm version, 1400 rpm version is only 8 watts).  I would have thought that this would not have been powerful enough to drive your little Unimat.  From memory, the original Unimat motor was about 95 watts.

Dave
The Emerald Isle


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## Mr blue in the dark (Apr 12, 2020)

deverett said:


> Attached is a wiring data sheet from Parvalux to help you.  The capacitor you require is 2.5Mfd.
> I note that your SD21 motor has only a maximum power of 20 Watts (2800rpm version, 1400 rpm version is only 8 watts).  I would have thought that this would not have been powerful enough to drive your little Unimat.  From memory, the original Unimat motor was about 95 watts.
> 
> Dave
> The Emerald Isle



Thanks for the info!! 
That's not good news lol, i took a chance with it as it was a quarter the price of a Emco replacement motor.
Ill will wire it up as per the diagram you have kindly attached, and see how it goes. I'm sure ill find some other use for it if its not up to the job.

cheers


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## stevehuckss396 (Apr 12, 2020)

This is from the manufactures website  "The Parvalux SD21 is a single-phase AC induction motor with permanent capacitor"

If it were me, I would try this one. Should have a capacitor already built in.


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## bluejets (Apr 13, 2020)

That motor will not, as they say, pull the skin off a rice pudding.
It's a cap run motor with very little torque and as it loads up it will simply stall.
Not only in power output either.
Original motors on these small lathes are generally series ( brushed) motors and for a reason, and controlled via a speed controller.
As load comes on, both the field windings and the armature draw more current resulting (on AC) in a form of speed self regulation.


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## franscubitt (Apr 14, 2020)

I had the same problem so bought a cheap hand drill and made a frame to hold it behind my Unimat. Works like a bomb i have had mine rewired but if you do that nake sure you tell the Rewinders it runs clockwise not counterclockwise as per normal 
Hope this helps


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## deverett (Apr 14, 2020)

The original Unimat motor looked like a typical sewing machine motor.  The later U3 lathes had motors double the power but were only rated at 50% duty (10 mins on, 10 mins off).
So, if looking for a new motor for your SL, then consider getting a more powerful motor than original and one that has 100% duty cycle.

Give me your email address in a private message and I can send you a copy of the book 'Making the most of the Unimat'.

Dave
The Emerald Isle


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