Patent ID: 6041605
Filing Date: 2000-03-28
Classification: F25B

Abstract:
In a microprocessor controlled system including a motor, a compressor driven by the motor, a condenser, an expansion device, an evaporator, means for supplying refrigerant for cooling the motor, and compressor regulating means, a method for providing refrigeration responsive to a signal indicating a requirement for refrigeration including the steps of:supplying power to an electronic module which is thereby placed in a power-on reset start-up routine including the serial steps of:a) determining static discharge pressure;b) starting the compressor;c) determining the discharge pressure; andd) if the discharge pressure is more than 10 psi below the static discharge pressure within fifteen seconds after starting the compressor, the compressor is stopped;sensing the motor temperature;sensing the discharge temperature;if the sensed motor temperature is at or above a first temperature, liquid refrigerant is supplied to the motor until the first temperature is lowered by a first predetermined amount;if the sensed motor temperature exceeds the first temperature by a second predetermined amount, the motor is shut off;if the sensed discharge temperature is at or above a second temperature, liquid refrigerant is supplied to the motor until the second temperature is lowered by a third predetermined amount;if the sensed discharge temperature exceeds the second temperature by a fourth predetermined amount, the motor is shut off.