reduce the speed of a single phase induction motor

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** Just feed it with 25 or 30 Hz sine wave at about half voltage.

Or if that is a problem, use a gear or belt reduction system.

** 24hrs, no problem.

But after that it is totally buggered.

.... Phil

gle phase induction motor to about 50%?

late ratings observed)

What we would need is horsepower, operating voltage, then anticipated maxim um load.

These exist, but as the load increases, so does the cost.

As to operational capacities, if the motor is rated as "continuous" and pro perly cooled, there should be no issue about how long it runs as long as it is within its design load. NOTE: "Design Load" is generally some amount le ss than "Maximum Load". But not too much, typically around 10% - so you nee d to know which "90%" you are measuring.

ine-motors-actual-load/

Gives you more on the subject.

Peter Wieck Melrose Park, PA

On Mon, 7 Oct 2019 16:04:45 -0700 (PDT), snipped-for-privacy@gmail.com wrote:

It depends on what type of single phase induction motor. The typical single phase motor that you see powering bench grinders and the like will often have a centrifugal starting switch, a potential relay, or an electronic switch that controls the starting winding. These cannot be made to run at 1/2 speed without extensive modification and a power supply that provides AC at 1/2 the frequency the motor is rated for. Other common motor types may not have any type of switch and instead use a capacitor permanently connected to one winding to shift the phase. These motors would also need the 1/2 frequency. The reason for the 1/2 frequency is that the speed of most induction motors depends on frequency. If the voltage is lowered the motor will start to slow and will then consume more current in an effort to speed back up to normal operating speed. If the voltage gets too low the motor will just stall and then will overheat and eventually burn up if the power supply can deliver enough current. This stalling will happen way before the motor drops to 1/2 speed. Shaded pole induction motors are controllable to some extent by lowering the voltage. These motors are not very efficient. They are mostly used for applications requiring little torque, like the turntable in a microwave oven. Shaded pole motors are sometimes used for fans and controls for these can be bought at any store that sells home improvement stuff. Shaded pole motors have a tiny starting torque and so are not practical for anything other than starting very light loads, such as fans and turntables. Their speed regulation is also poor as it is quite sensitive to load changes. Unfortunately there is no simple way to lower by 1/2 the speed of a typical single phase induction motor. Eric

As folk have said, that's not a simple thing. There are various ways but all have issues, in some case the issue is just cost/complexity.

if it's rated to run continuously at 90% or greater load, yes. Otherwise no.

NT

Thanks to you all. you ve all given me a great deal of knowledge.