Three-phase submersible deep-well pump AC motors don't require starting capacitors, run capacitors, or centrifugal starting switches that can wear out and fail. They operate with a higher torque and greater efficiency than single-phase submersible deep-well pump motors of the same HP, rpm, and frame size.

Capacitor-start submersible deep-well pump AC motors use a capacitor to provide additional power during startup for a higher starting torque. This provides more starting torque than split-phase motors while creating better efficiency.

Split-phase submersible deep-well pump AC motors have a less powerful, smooth, and softer startup for use with pumps that must gradually come up to speed after startup.