Maintenance of variable frequency drive, fan belt and pulley


Variable frequency drive, fan belt and pulley are core components of a fan and they are critically important to the reliable and durable operation of the fan. Proper maintenance helps to deliver good fan performance and must be performed by professional personnel according to standard procedures. The following are the common procedures that INFINAIR recommends for the maintenance work to be properly carried out.     

Variable Frequency Drive

  • The variable frequency drive shall match the motor.
  • Always check the ampere (current value) of the motor during adjustment.
  • Be sure to check the rated speed of the fan and then adjust the frequency. Do not exceed the rated speed to avoid overload or malfunction.

Belt/ Pulley

  • Check periodically (every six months) the alignment of pulleys and belt tension. Pulley displacement and loose belt may cause vibrations, sound, system loss and even premature wear and tear.
  • After the first 24 hours of continuous running, the fan shall be shut down to adjust the belt tension according to 5.9 and 5.10.
  • When replacing the old belt, a new belt of the same model shall be used.
  • When replacing one belt, all the other belts that drive the fan shall be replaced at the same time.
  • The taper bore bushing type pulley, the advanced of its kind, is used.
  • When adjusting the pulley alignment, it only needs an Allen wrench to loosen the set screws on the taper bore bushing. Then screw them into the disassembling hole and tighten them to remove the pulleys.
  • The screw thread of the installation hole is found on the pulley and that of the disassembling hole on the taper bore bushing. (See Figure below)