Descrizione del motore

Efficiency Y series high voltage motors can be operated when the nominal frequency is either 50 Hz or 60 Hz. As motor utilisation and size are related to torque and not power, the theoretical power of single-speed motors increases linearly with the supply frequency (and therefore speed), i.e. by 20% from 50 Hz to 60 Hz.

I2R winding losses are especially dominant in small and medium-sized induction motors. They basically remain constant at 50 Hz and 60 Hz, as long as the torque is kept constant. Although friction, windage and iron losses increase with frequency, they play a minor role especially in motors with a number of poles of four or more. Therefore, at 60 Hz, losses increase by less than the 20 per cent increase in power compared to 50 Hz and, consequently, efficiency is improved.

In practice, the 60 Hz and 50 Hz power designations of single-speed motors have to comply with standard power levels according to IEC 60072-1 and local standards such as EN 50347. Therefore, an increase in the motor's power rating by 20 per cent is not always possible. However, the general advantage of 60 Hz still applies when the motor design is optimised for the respective power frequency rather than just being reclassified. The difference in efficiency between 50 Hz and 60 Hz varies with the number of poles and the size of the motor. In general, the efficiency of 

Motor Parameters