The maximum performance that the electric motor will present will depend on the materials used in its manufacture and the dimensions of the same. In general, the yield reaches values around 98% for large engines. Low-power single-phase motors have low yields, up to 50%.
There are currently over-normal electric motors, called high-performance motors, which have higher costs, but the energy savings provided will allow the additional cost to be offset. The rated output will depend on the design of the motor, varying with the load on the motor shaft.
The service factor simulates a power reserve that the motor has and can be used on a continuous basis. The power that is obtained from the motor is the rated power that is indicated on the board, which is multiplied by the service factor.
The service factor should not be confused with the momentary overload of the electric motor, which is valid for short periods of time. An overload indication is: 60% of rated power for 15 seconds.
Even electric motors with service factor 1.0 have a certain overload capacity for a limited time.