The output drop of centrifugal fan may be caused by unbalanced impeller

The following reasons may exist for the decrease of centrifugal fan output:

1: Motor fault, such as local short circuit of motor stator winding, causes speed drop

2: The impeller may have dirt to increase the load and affect its speed

3: Impeller is unbalanced (abnormal vibration will occur at the same time)

4: Whether the air inlet is blocked by substances, such as the air inlet valve is turned down or the air inlet filter screen is dirty and blocked.