What percentage increase in motor torque is generally provided by a start capacitor?

The typical percentage increase in motor torque provided by a start capacitor is approximately 250%. Start capacitors are used in single-phase induction motors to create a phase shift in the electrical current, which generates additional starting torque that is crucial for initiating the rotation of the motor under load.

When the motor is started, the start capacitor temporarily boosts the current flowing to the motor's start winding, resulting in a significant increase in torque. This added torque helps the motor overcome the initial inertia and load conditions during startup. Once the motor reaches a certain speed, usually around 70% to 80% of its rated speed, the start capacitor is disconnected by a centrifugal switch or relay, allowing the motor to operate efficiently on the run winding.

The value of ~250% indicates a robust enhancement of torque compared to motors that do not utilize start capacitors, aligning with the typical performance of such capacitors in enhancing startup capability. This characteristic is vital for applications where starting under load is necessary, making them a common solution in many residential and commercial motor applications.