Compressor loading control

A system comprising:

• a compressor;
• a condenser;
• a discharge line, coupling the compressor to the condenser to carry refrigerant from the compressor to the condenser;
• an expansion device;
• an evaporator;
• a suction line, coupling the evaporator to the compressor to carry refrigerant from the evaporator to the compressor and comprising a first and second parallel segments;
• an electrically actuated valve in the first segment;
• means for rapidly pulsing said electrically actuated valve in the first segment whereby the rate of flow in said suction line to said compressor is modulated;
• a fluid path extending from a point intermediate said condenser and said expansion device to said compressor at a location corresponding to an intermediate point of compression in said compressor;
• a bypass line connected to said fluid path and said suction line;
• an electrically actuated valve in said bypass line;
• means for rapidly pulsing said electrically actuated valve in said bypass line whereby the rate of flow of bypass to said suction line is modulated;
• an economizer circuit connected to said fluid path;
• an electrically actuated valve in said economizer circuit;
• and
• means for rapidly pulsing said electrically actuated valve in said economizer circuit whereby the rate of economizer flow to said compressor is modulated.