Abstract: A water pumping system, a motor drive, and a method of starting pumping by the motor drive. The method includes powering the electric motor with a motor drive; driving a progressive cavity pump with the electric motor; monitoring a speed difference between an electrical speed and an observed speed of a rotor of the electric motor; and performing a protective action as a function of the speed difference.

Abstract: A water pumping system, a motor drive, and a method of starting pumping by the motor drive. The method includes performing repeated starting attempts to overcome stiction in a progressive cavity pump by attempting to supply power to an electrical motor at increasing power levels in each starting attempt and supplying the power at the increasing power levels if the power is available in from a power source; and after each starting attempt: reducing the power applied to the electrical motor to a reduced power level; determining a rotational speed of the electrical motor; determining if the rotational speed matches a speed corresponding to the reduced power level applied to the electrical motor; if the rotational speed does not match and a predetermined number of starting attempts has not been reached, performing a next starting attempt; and if the rotational speed does match, entering a normal mode of operation.

Abstract: A water pumping system, a motor drive, and a method of starting pumping by the motor drive. The method includes performing repeated starting attempts to overcome stiction in a progressive cavity pump by attempting to supply power to an electrical motor at increasing power levels in each starting attempt and supplying the power at the increasing power levels if the power is available in from a power source; and after each starting attempt: reducing the power applied to the electrical motor to a reduced power level; determining a rotational speed of the electrical motor; determining if the rotational speed matches a speed corresponding to the reduced power level applied to the electrical motor; if the rotational speed does not match and a predetermined number of starting attempts has not been reached, performing a next starting attempt; and if the rotational speed does match, entering a normal mode of operation.

Abstract: A water pumping system, a motor drive, and a method of starting pumping by the motor drive. The method includes powering the electric motor with a motor drive; driving a progressive cavity pump with the electric motor; monitoring a speed difference between an electrical speed and an observed speed of a rotor of the electric motor; and performing a protective action as a function of the speed difference.