I have a Hydro-Air HA 430 single phase 1hp motor and would like to change it to 2 speed, is there a way to run it at a slower speed as i need to run it as a circulation pump but when i flick a switch it comes on to full power.
A single speed capacitor start motor can not be "speed controlled".
Well, okay maybe in some very rare cases, but only if the low speed is still fast enough to operate the centrifugal cutout switch or some other means of removing the capacitor is provided.
JBD, I agree with you mate. A Cap Start Motor needs to run up to 75% of Full Load Speed to open the C/Switch. If it doesn't, the start winding will burn out.