Next week I bring home a new to me lathe that has a 7.5 hp 3 phase motor. My garage shop power is limited to a 240 volt / 40 amp circuit (unused dryer outlet) so I plan to run a VFD to supply power to the machine. I have two questions:
(1) Can I run a 10 hp VFD to power the 7.5 hp motor?
In reading other posts, it appears that the ideal setup would be to run a VFD that’s 2x the rated motor hp. My concern is that if I did that I’d pull more amps than the 40 amp circuit has available. Is it viable to run this motor on a 10 hp VFD without tripping my breaker repeatedly? I don’t plan on machining very heavy loads that would strain the motor. I’ve considered replacing the motor with a 5 hp alternative but I’d rather not buy a new motor if I can avoid it.
(2) Should I setup VFD just as power source or tie in control panel buttons?
Can I use the VFD just as a power source or do I need to rewire the control panel relays / switches for power on/off, jog, forward/backward & e-stop? I don’t plan on using the VFD for variable motor speed control so it seems easier to use it only as a power source and rely on the lathes existing wiring to handle all the usual features.
This will be my first VFD installation so I’m new to the whole configuration options.
(1) Can I run a 10 hp VFD to power the 7.5 hp motor?
In reading other posts, it appears that the ideal setup would be to run a VFD that’s 2x the rated motor hp. My concern is that if I did that I’d pull more amps than the 40 amp circuit has available. Is it viable to run this motor on a 10 hp VFD without tripping my breaker repeatedly? I don’t plan on machining very heavy loads that would strain the motor. I’ve considered replacing the motor with a 5 hp alternative but I’d rather not buy a new motor if I can avoid it.
(2) Should I setup VFD just as power source or tie in control panel buttons?
Can I use the VFD just as a power source or do I need to rewire the control panel relays / switches for power on/off, jog, forward/backward & e-stop? I don’t plan on using the VFD for variable motor speed control so it seems easier to use it only as a power source and rely on the lathes existing wiring to handle all the usual features.
This will be my first VFD installation so I’m new to the whole configuration options.