A PSC (Permanent Split Capacitor) motor is a single-phase induction motor with a capacitor permanently connected in the start winding circuit. PSC motors power furnace fans, air handler blowers, and compressors in residential HVAC systems. The capacitor remains active during startup and operation, eliminating the need for centrifugal switches and improving reliability.
Performance Characteristics
PSC motors typically operate at 1/4 to 1 horsepower with motor speeds between 1,200 and 3,600 RPM. These motors have lower starting torque than capacitor start-induction-run motors but consume less power. PSC motors operate 85% to 90% efficient when sized properly for their application, with power factors improved to 0.85 to 0.95 by permanent capacitor connection.
Advantages and Applications
PSC motors provide simpler construction with fewer moving parts, reducing maintenance needs and failure points. Single capacitor connection simplifies troubleshooting during service calls. These motors work reliably in variable-speed applications where ECM (electronically commutated motor) technology is not required, making them cost-effective for budget-conscious installations.