A single phase motor in which the capacitor remains connected when the motor runs is called?

A single phase motor where the capacitor remains connected during operation is referred to as a Permanent Split Capacitor (PSC) motor. This design allows for continuous assistance in starting and running the motor, leading to better efficiency and performance throughout its operation.

In a PSC motor, the capacitor is permanently connected in series with the starting winding. This configuration provides a phase shift, which is necessary for generating the rotating magnetic field that is crucial for motor operation. Unlike capacitor start motors, which only use the capacitor during startup and disconnect it afterward, the PSC motor relies on the capacitor continuously. This feature allows for smoother operation, reduced starting torque requirements, and more efficient energy use during normal running conditions.

Other types of motors mentioned, such as split-phase motors and induction motors, operate on different principles. While split-phase motors do utilize capacitors, their configuration doesn't involve a permanently connected capacitor throughout the motor's operation. Induction motors, on the other hand, rely on an electromagnetic induction process to operate without capacitors for phase shifting.

Identifying PSC motors is important, especially when considering applications that require continuous operation with a reliable starting and running mechanism without the need for complex electrical circuitry.