is it possable to make a single phase 1hp motor run variable speeds. i have been told no can u prove otherwise

Question

i have been told this can only be done with three phase motors .
single phase dont handle it.

Answer 1

Variable speed operation of single phase (1ph) motors is very limited. There are variable frequency drives (VFDs) that are designed to operate specific types of 1ph motors. The only suitable motors are permanent-split capacitor (PSC) and shaded pole motors. Switched-capacitor motors (cap-start or cap-start/cap-run), and split-phase motors are not suitable for VFD operation. Also, VFDs should not be used for loads that require high starting torque or high torque at low speed. Fans and centrifugal pumps are OK, but other types of loads would be questionable.

If you already have a PSC or shaded pole motor installed, you could add a VFD that is designed for single phase motors. If you don’t have a motor or have a motor that is not suitable for VFD use, the best choice for operation from single phase power is buy a three phase motor and a VFD that converts single phase input power to three phase output. These are available in both 120V, 1ph input / 230V, 3ph output and 230V, 1ph input / 230V, 3ph output. A universal (AC/DC) motor with a matching light dimmer type controller is another good alternative.

Here are links ton a VFD for single phase motors. I think that there is at least one other brand available.
http://www.anaconsystems.com/text/opti_1.html
Be sure to read the information about motor and load limitations:
http://www.anaconsystems.com/text/support.html

There are a number of VFD brands that offer single phase input with three phase output. Here is a link to one that sells VFDs and motors on line:
http://web4.automationdirect.com/adc/Shopping/Catalog/AC_Drives_-z-_Motors

Answer 2

Single Phase Variable Frequency Drive

Answer 3

This Site Might Help You.

RE:
is it possable to make a single phase 1hp motor run variable speeds. i have been told no can u prove otherwise
i have been told this can only be done with three phase motors .
single phase dont handle it.

Answer 4

Single Phase Vfd

Answer 5

Yes.
There are devices that attach to motors called 'variable frequency drives' (VFD). The make VFDs for 1-pahse motors, so you can vary the speed.

For something as small as a 1-HP motor it's kind of a waste, though. You'd spend way more money on the VFD than you would on the motor, itself. But, if you really need a variable speed, AC, 1-phase, 1 HP motor, that's the way to go.

For something that small, I would go with a universal (AC/DC) motor and operate it with a large variac.

.

Answer 6

I have several fractional horsepower single phase motors in my garage that run variable speeds:

My electric drill
My Dremel tool
My orbital sander

all of these are <$100, so the solution must be cheap

Just find a schematic for how these things do it.

Answer 7

Yes, of course. You can use variable frequency drives to run 1 hp motor with variable speed.

Answer 8

As tinfoil666 says, you have several in your house at the moment, add a sewing machine, food mixer and engraving tool to the list.