Abstract: The present application relates to a power failure controller for an electronically controlled expansion valve in a refrigeration system. The valve is controlled by a valve controller configured to close the valve as a part of a power-up routine when the valve controller is first powered-up from a powered-down state. The power failure controller includes a circuit configured to allow the valve controller to enter the powered-down state when a power failure is detected and to subsequently provide power to the valve controller from a capacitor bank coupled to the circuit so that the valve controller conducts the power-up routine and closes or mostly closes the valve.

Abstract: The present application relates to a power failure controller for an electronically controlled expansion valve in a refrigeration system. The valve is controlled by a valve controller configured to close the valve as a part of a power-up routine when the valve controller is first powered-up from a powered-down state. The power failure controller includes a circuit configured to allow the valve controller to enter the powered-down state when a power failure is detected and to subsequently provide power to the valve controller from a capacitor bank coupled to the circuit so that the valve controller conducts the power-up routine and closes or mostly closes the valve.

Abstract: A step motor valve assembly comprises a housing including a threaded portion, a rotor having rotational axis and a threaded portion in threaded engagement with the threaded portion of the housing such that rotation of the rotor will effect axial movement of the rotor relative to the housing, a valve member carried by the rotor for axial movement toward and away from a valve seat upon rotation of the rotor in respective opposite directions, and a return mechanism for moving the valve member to a fail-safe position upon a loss of power to the step motor valve assembly.