A High-Power-Factor One-Running-Capacitor 2-Motor System

This paper describes the theory and test results of a proposed system which operates one phase of the fan motor in series with the running capacitor of the compressor motor in an air-conditioning unit. With a fan motor having nonquadrature concentrated windings, the following points have been established: 1. The over-all power factor, efficiency, and starting torque compare favorably with a system employing a separate permanent capacitor fan motor. 2. There is a good possibility that the motor cost is comparable with that of a shaded-pole motor. While the winding cost is higher than that of a shaded-pole motor, the motor size is considerably reduced. This is possible, as the efficiency of the new motor is comparatively high. It is expected that the reduction in material cost might be sufficient to offset the higher winding cost. 3. There is no detrimental effect on the compressor motor whatsoever. 4. The required running capacitor and control switch are the same as conventional systems for both single-speed and 2-speed operations.