The service factor shows a power accumulation that the electric motor holds and can be used on a continuous basis (this type of regime is also known as S1, in accordance with national and international standards).
The power that can be extracted from the motor is thus the nominal power (signaled on the board) multiplied by the service factor. A power motor of 5 kW and with a service factor of 1.15 can operate continuously with 5 ⋅1.15 = 5.75 kW in continuous mode. When a service factor is not assigned, it means that the engine does not fear accumulation of power.
When the power actually used corresponds to the nominal power multiplied by the service factor, a temperature rise of 100 C above the temperature limit of the insulation class of the motor must be considered.
In compliance with the standards, when the service factor is applied, there may also be changes in some of the motor properties, such as power factor and efficiency. However, starting torque, maximum torque and starting current do not need to be changed.