HVAC Excellence Electrical Certification Practice Exam

The capacitor start-capacitor run (CSCR) motor is specifically designed to deliver both high starting and running torque, making it ideal for applications requiring a significant amount of power right from the start, such as in air conditioning compressors and other HVAC applications. This motor uses one or more capacitors that are switched into the circuit to provide a boost of voltage, facilitating a strong starting torque. Once the motor reaches a certain speed, these capacitors are often taken out of the circuit to maintain efficiency while still providing substantial running torque.

This capability to deliver high torque during both the startup and running phases is a unique characteristic of CSCR motors compared to other motor types. For instance, a capacitor run motor does provide some starting torque but not as high as that of a CSCR motor. Induction motors typically have lower starting torque compared to CSCR motors, and permanent split capacitor motors usually achieve lower torque as well, lacking the high initial boost that a CSCR motor can provide. Thus, the CSCR motor stands out for applications that demand both reliable start-up and sustained operational power.