A motor and a rotary potentiometer, or other position sensor, running on the motor shaft are mounted in a first enclosure with an output shaft for driving a power switch open or closed. A part of the system outside the first enclosure makes use of a motor position signal from the rotary potentiometer that is processed by a microcontroller that a worker can interact with at a switch panel to set and adjust motor travel limits without needing access into the motor enclosure. The first enclosure and its components can be used for various applications, including those for either underground or pad-mounted switches, which for the latter case can have the first enclosure inside a second enclosure on a pad, and the second enclosure also contains other power and control elements of the system. A portable unit with the switch panel for travel limits can be provided. Other features include a slip clutch, for running a rotary potentiometer from the motor shaft, an overspeed brake of one or more voltage suppressor elements for limiting the speed at which the motor can be turned during a manual switch operation, and a compact, economical structure of the first enclosure.