induction motor speed

Yes and no. There are variable frequency drives that allow this but not all induction motors lend themselves to this service. The mechanical load and the speed range must be considered. Motors can get very hot very fast!

"exxos" schreef in bericht news:41dd61a2$0$16589$ snipped-for-privacy@news-text.dial.pipex.com...

You're wrong.

petrus bitbyter

I suspected altering the frequency was the key, Voltage changes nothing, probably not so much of a easy task to alter frequency of the motor, unless you work for a large power company and alter the mains down to around 25hz :-)

Chris

This is accomplished with an inverter. The problem is that a 60 Hz (or 50 Hz) motor does not have enough iron in it to allow efficient 25 Hz operation. The motor will run hot due to not having enough inductive reactance at the reduced frequency. Dropping down to 10 Hz would make it even worse. A motor designed for variable frequency drive has more iron. Also, it might use a different iron/steel alloy to allow efficient operation at higher frequencies (say 400 Hz).

With a light mechanical load and a good motor, it's sometimes possible to get a reasonable speed range using a variable frequency inverter.

"Charles Schuler" schreef in bericht news:d snipped-for-privacy@comcast.com...

A good one controls both frequency and voltage. The better ones even take into account that at very low speeds the resistance of the coils cannot be negelected.

petrus bitbyter