AC fans are the fans that are powered by alternating sinusoidal electric current. These fans are powered by positive current and the same amount of negative current. The general frequencies of AC voltage for the AC fans are 100 volts, 120 volts, 200 volts, 220 volts, 230 volts, and 240 volts at max. AC fan motor rotates at 50rpm that means the blades rotate 50 times per second of operation. AC fans are designed for a specific rotation frequency of 50 Hz, however, they can be customized for the speed and airflow rate if there is an essential requirement.