Electronic method for starting a compressor

Abstract

A motor starting apparatus (10) includes a motor starting relay (112) to switch a motor starting capacitor (110) into a motor circuit across a run capacitor (111). The system control (116) includes an electronic voltage measurement circuit to measure a winding voltage (113, 114) of the motor winding (102, 103). The system control (116) also includes a microprocessor to run an algorithm that causes the system control to switch the starting capacitor (110) out of the motor circuit when a measured winding voltage (113, 114) exceeds a winding voltage threshold. A method to start a motor includes the steps of determining a motor winding voltage (113, 114) threshold; closing the motor starting capacitor relay (112) when needed; closing a contactor (108, 109) to supply power to the motor starting apparatus and the motor circuit; measuring a winding voltage (113, 114); comparing the measured winding voltage (113, 114) to the voltage threshold; and opening the starting capacitor relay (112) when measured winding voltage (113, 114) exceeds the voltage threshold indicating that the motor has been started.

Dependencies are inferred from the claim text.