Quote Originally Posted by Robin Hewitt View Post
Don't you have to have a centripetal switch as well as the capacitor?
No centripetal switch, the additional start capacitor circuitry to provide enough phase shifted power to start the motor (which must be disconnected for run conditions) can be on a timer relay or be switched using voltage sensing, it used to be common for rotary converters to be spun up using a rope with a knot at the end on a pulley with a slot in one side, if you had end access to the motor you could even use a starting handle ;-)

I bought and read books on all this stuff before discovering Inverter VFDs, if you need a machine running next week, or tomorrow VFD is the way to go, if you have no time pressure you can get a machine running with caps, relays and miscellaneous gubbins but the VFD driven machine will be smoother and better.

- Nick