Control system for compressor motor used with air-conditioning unit

Claim 1

A control system for a compressor motor of an air condition unit comprising a refrigerant compressor having the compressor motor, an outdoor coil, a restrictor, and an indoor coil, said control system comprising: (a) an operation switch, (b) a microcomputer connected to said operation switch and including timer, a processing circuit and a memory for storing data on a rotating magnetic field generation signal capable of supplying a first current for generating a rotating magnetic field to the compressor motor and data on a non-rotating magnetic field generation signal capable of supplying a second current for generating a non-rotating magnetic field, said memory being supplied from the operation switch with data designating the operation start time of the heat pump, which data is stored in said memory, said microcomputer introducing data for generating a non-rotating magnetic field from said memory before the heat pump start time thereby to generate a non-rotating magnetic field generation signal, said microcomputer further introducing data for generating a rotating magnetic field from the memory after said start time to generate a rotating magnetic field generation signal, (c) compressor motor drive means inserted between said microcomputer and said compressor motor and supplied with a non-rotating magnetic field generation signal and a rotating magnetic field generation signal from the microcomputer, said signals being applied to said compressor motor, (d) outdoor air temperature detection means for detecting the outdoor air temperature θ H , (e) means for providing a start time T (θ H ) to start introduction of the data for generating a non-rotating magnetic field from said memory in accordance with the outdoor air temperature θ H , and (f) means for starting generation of a signal for generating a non-rotating magnetic field at the start time T (θ H ).