Installation
To ensure proper fan performance as cataloged, caution must be exercised in fan placement and connection to the ventilation system. Obstructions, transitions, poorly designed elbows, improperly
selected dampers, etc., can cause reduced performance, excessive noise, and increased mechanical stressing. For the fan to perform as published, the system must provide uniform and stable airflow into the fan.
Uniform Flow | Improperly sized or | Elbow too close |
| obstructed damper | to fan inlet |
Wheel Rotation
A common problem is wheel rotation in the wrong direction. For centrifugal fans, incorrect wheel rotation will provide some airflow. However, the airflow will be far below the cataloged value. Rotation should be checked while the fan is coasting to a stop. Proper rotation for the most common wheels are shown below.
When connecting a 3 phase motor, there is a 50% chance that the fan will run backwards. Changing any two supply power connections will reverse the direction of rotation.
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