Maybe it's my monitor or something because both are clear as a bell here. Internet is 30M here.
Anyway, I found a couple more engineering manuals online (did I ever mention that I hate Google)
The weak link in submersible well pump motors are the bearings.
The bearings can not function properly at motor speeds of less than 30Hz for specified durations, or you will toast them.
Franklin and Goulds are a straight line ramp to operating speed with no longer that 1 second below 30Hz.
Grundfos is a straight ramp to 30Hz in 3 seconds, then you can do anything you like after that to 60Hz.
Franklin had a disclaimer that their motors are not inverter rated, but will work between 30-60Hz. They also stated that you should not restart the motor for at least 7 minutes after it was turned off.
Grundfos seems to be the best choice so far. You can do a pretty decent soft start within their parameters.
A hard start is where you turn a motor on and your lights go dim for a second or so. That's because it is sucking a whole bunch of juice to get it going to full speed. A soft start gradually gets things going so it slowly applies the juice to the motor. No light dimming effects.
Based on this new info., there is no way a well pump in the 10HP (or even smaller) range could be controlled, due to mechanical limitations, that could draw me a glass of water based on only controlling the motor.
The high end side of things it a totally different story tho.
Maybe a new post should be started, instead of hijacking others
