Aluminium Series
Inverter Rated Motors
Frequency Inverter Or VFD Duty
Machine tools and process equipment can perform better if the speed of the prime mover can be controlled. This requirement leads to use of Variable Frequency Inverters or Drives, popularly known as VFDs in combination with the electric motors. It is advisable to use Inverted Rated motors while controlling the motor through VFDs. Invert Rated Insulation protects the motor from voltage spikes and surges generated while operating the motor with VFDs. Depending upon the requirement, motor can be selected.
(A) Where speed of the motor is to be reduced approximately up to 50% of the rated speed. An integral (directly driven) fan mounted on the motor shaft provides sufficient cooling (IC41 Cooling). Hence only insulation system becomes important which provides protection against voltage spikes and surges.
(B) Where the speed of the motor to be reduced further the integral fan mounted on the motor shaft becomes inactive OR when the speed of the motor is to be increased with a frequency above 60 Hz, the integral fan overloads the motor.