For our popular range of ring and grid mounted fan assemblies we are often asked by manufacturers and engineers alike which are our recommended restrictions on motor power and what size blade they can drive.

Using the wrong combination can cause premature failure of the motor; if a blade is undersized for the motor there will be insufficient airflow to keep the motor cool which results in overheating and failure normally of the bearings or winding. Likewise if a blade is used which is oversized for the motor then the motor will also have an increased chance of failure as the motor is not powerful enough to turn the blade at a sufficient speed to cool the motor, both cases result in the same failure.

Our guidelines for motor and blade matching in order to achieve maximum airflow coupled with a long motor life are: