Run capacitors are designed for continuous duty while the motor is powered, which is why electrolytic capacitors are avoided, and low-loss polymer capacitors are used. Run capacitors are mostly polypropylene film capacitors (historically: metallised paper capacitors) and are energized the entire time the motor is running.[1] Run capacitors are rated in a range of 1.5 to 100 µF, with voltage classifications of 370 V or 440 V.
Low dissipation factor,small inherent temperature rise.excellent self-healing stability,safety and high voltage withstand,etc.