If you buy something other than a Franklin drive for your pump, be very careful. As valveman stated, if you don't reach 30 Hz (half speed) in one second or less, you will damage the bearing in the bottom of the motor. The Kingsbury thrust bearing hydroplanes for lubrication. This doesn't happen until half speed, get there as quick as possible. A 3hp well pump will need to be 3 phase to make it variable speed, so that means a new motor and drive.
If you do a Franklin SD30 (for the 3 hp) you can do a 3 phase motor (cheaper than 1 phase) a 1.5 hp pump (because it will overspeed) and smaller wire (becasue of the 3 phase) and the drive unit. It would be a nice system and your generator will thank you.
If you do a Franklin SD30 (for the 3 hp) you can do a 3 phase motor (cheaper than 1 phase) a 1.5 hp pump (because it will overspeed) and smaller wire (becasue of the 3 phase) and the drive unit. It would be a nice system and your generator will thank you.