VFD Assistance

[Masterjuggler]

Suther51,

I'll admit it can definitely be hit or miss with those cheap Chinese VFDs. Problem is the cost for a "real" one is prohibitively expensive. It's also far better than the next cheap alternative, start/run capacitors. I tried that route and hated it. Can't get full torque, no speed control, have to tailor to the motor, and annoying to use.

For the application, a 2x72 grinder, it's almost never fully loaded to stall. I haven't been able to stall my 2HP motor even putting my full body weight on it, so a 3HP gives that much more overhead as it is. If it were running a mill or something with constant heavy load it'd be good to oversize the VFD I'd imagine.

Maybe someone with more in-depth knowledge has differing advice, I'm certainly not the expert on it.