Balancing Extractor Fan

1. Remove worn blades and clean the fan hub.

2. Inspect the hub for cracks or damage.

3. Install new matched blades, bolts, lockwashers, nuts, and Loctite 271.

4. Pull blades outward against the bolts to remove any play in bolt holes.

5. Torque bolts to 109-122 N·m (80-90 Lb-Ft).

6. Bolt the hub assembly in a vertical position to a test bearing mounted flange (P/N 1190289732 - shown at right), and number each fan blade.

7. To check balance, bring each blade to the 12 o'clock position to see if it remains there or if it causes the fan to spin. The heavier blade will stop at the 6 o'clock position, which shows it needs to be modified.

8. Balance blades by grinding tips of blades. Do not weld blades, as distortion may occur. Repeat step 7 until fan is balanced.

9. A balanced fan is one in which each blade will stay at the 12 o'clock position when mounted on a frictionless axis. It is critical to balance fan blades precisely.

CM053510038
CM053510039

AG,T803584,216 -19-07JUN00-1/1