MECHANICALLY OPERATED PRESSURE SWITCH HAVING SOLID STATE COMPONENTS

摘要

A pressure switch having mechanical and solid state components. The switch includes mechanical components that are arranged so the mechanical components provide the electrical connections between a motor and an electric source for the motor. The mechanical components include a fluid pressure responsive mechanism which causes contacts of the switch to move with a snap action in response to pressure variations in a fluid system. The solid state components detect variations in the motor current, voltage and power factor as well as the duration of the intervals during which the motor is energized and interrupts or prevents energization of the motor when at least one of the variations exceeds a preprogrammed value. The switch includes a calibration switch which programs the switch operation for use with the particular motor controlled by the switch and coded diodes that function to indicate the cause of a malfunction detected by the switch.