Using A Variac For Speed Control

[LewSchiller]

I did a search and didn't come up with anything so thought I'd ask.

I have a Variac and just now tried it out on a clutch motor machine.

The Variac was able to reduce the motor speed and in turn that reduced the machine speed at the lowest point of operation with the foot control.

I found it interesting that there aren't any threads or comments on the subject. Is there a reason why this method wouldn't work in practice?

This would be for home production - not heavy shop use.

One concern could be that the cooling fan on the motor would be reduced in speed...but then the motor shouldn't be generating as much heat.

Thanks!

Lew

Edited September 1, 2013 by LewSchiller

[Trox]

I am no electrician but I am afraid that will ruin you motor, its variates the voltage. Be careful that you do not burn your motor.

I use frequency converters on my 3 PH motors to control the speed like that, it also convert it to a single PH ( and loose a Little bit of its power, but it works well on 3 PH AC motors)

If you motor is a 3 PH it will work, if its a single PH its a different story I am afraid.

Then again, I am no expert

Tor

Edited September 1, 2013 by Trox

[LewSchiller]

It does reduce the voltage...and my short test was not done under any significant load.

[pcox]

You will lose a bunch of penetrating power.

[LewSchiller]

Yeah - probably not a good idea