Need Help!- POssible to Variable Speed of 2HP Motor?

[samsagaz]

Hi guys, i have an 2HP / 220v AC motor and i want to lower the RPMs because are too high for my work. THe motor are running at 3000RPM, i want to controll the speed. Exsit some circuit that let me do that?

Thanks in advance,

[Geof]

If the motor is a standard induction motor the only way is with a Variable Frequency Drive (VFD) and running the motor on a frequency lower than the design frequency in which case you will also lose some power.

[samsagaz]

Thanks, exist some VFD for 2HP motors? will cost too much? Im trying to design it. Hope someone can point me to some schematic.

[palenn]

http://www.anaconsystems.com/text/opti_e2.html
To control a single phase AC induction motor is very expensive and not sure if they go up to 2.0 HP. To control a 3 phase motor--$200-$300 for a VFD (variable frequency drive) and can be powered from 220VAC single phase.

[Al_The_Man]

You did not mention if it was 1ph or 3ph, 1 phase split phase induction motors are hard to control speed wise as they tend to fall out of run at low rpm or especially when a load is applied.
If you want 3 phase VFD design notes, I suggest you try some of the Semi manufacturers app notes, Freescale (motorola) Allegro, National Semi, etc.
Al.

[samsagaz]

Originally Posted by Al_The_Man You did not mention if it was 1ph or 3ph, 1 phase split phase induction motors are hard to control speed wise as they tend to fall out of run at low rpm or especially when a load is applied. If you want 3 phase VFD design notes, I suggest you try some of the Semi manufacturers app notes, Freescale (motorola) Allegro, National Semi, etc. Al.

its 1 phase

[Al_The_Man]

Originally Posted by samsagaz its 1 phase

In that case, I would not even try.
You are better off looking for a 3 phase motor or a DC brushed motor that you can control/build a mains operated SCR drive.
Al.