Electric Compressor Motor Pump Capacitor 5uF 450V

Motor Start Capacitors are used to boost the starting torque of single-phase electric motors by increasing the current through the start windings during startup. They typically only stay in the circuit for a few seconds before being switched off by a centrifugal or electronic switch inside the motor.   If your single-phase motor will not start, very often, the start capacitor (if it has one), could be bad.  It is a common failure mode in single phase motors.
A single phase motor will usually have both starting capacitors and run capacitors.  Run capacitors have a smaller capacitance rating than a starting capacitor and are designed for continuous duty operation because they stay in the circuit all the time.  It is important to never use a start capacitor as a replacement for a run capacitor because start capacitors are not designed for continuous duty.