Copeland Scroll Digital™ Compressors
The Copeland Scroll Digital™ compressor utilizes axial scroll compliance to achieve modulation by forcing the scrolls to separate, causing compression of the refrigerant to stop without stopping the compressor motor. In this “unloaded” state, the compressor output is at 0% capacity. When the scrolls are engaged in the “loaded” state, compressor output is at 100% capacity. The scrolls are separated in a 15 second periodic cycle to obtain a time-averaged compressor capacity based on the ratio of loading and unloading times. This allows the compressor to achieve infinite capacity modulation between 10% and 100%.
Inverter systems modulate refrigerant flow by varying the speed of the compressor motor.
The compressor motor speed determines the refrigerant flow speed. Therefore, by varying the motor frequency, capacity can be modulated. Capacity output increases and decreases with motor speed. Although this allows for precise temperature and humidity control, oil management hardware and electronics are needed to ensure enough oil is in the compressor during slow motor conditions and to ensure that too much oil does not get pushed out of the compressor during fast motor conditions.