IOM RB 10-95
TROUBLESHOOTING
PROBLEM
CAUSE
CORRECTIVE ACTION
System resistance is too high.
Check backdraft dampers for proper operation.
Remove obstructions in ductwork. Clean dirty
filters. Check for adequate supply air for
exhaust fans or exhaust air for supply fans.
Reduced airflow
Fan too close to damper.
Increase distance between fan and damper.
Unit running backwards.
See pre-starting checks.
Fan speed too low.
Increase fan speed.
Excessive dirt on propeller.
Clean propeller.
Bearings
Tighten bearing collars and set screws
Lubricate bearings. Replace defective bearings.
V-Belt drive
Tighten pulleys on motor and fan shaft. Adjust
belt tension. Align pulleys. Replace worn belts
or pulleys. See "Routine Maintenance".
Excessive Noise
Excessive vibration
Remove dirt build-up from propeller. Check all set
screws and fasteners for tightness. Check for
worn bearing. Correct propeller imbalance.
Check for loose dampers, guards or ductwork.
Defective Motor
Replace motor.
Motor load amperage must be checked and compared to nameplate rating to avoid serious damage to motor when speed is increased.
Belt Drive Fans Parts List
Direct Drive Fans Parts List
1. Fan Panel
2. Propeller
3. Drive Frame Channel (2)
4. Motor Plate
5. Motor
6. Motor Pulley
7. Shaft Pulley
8. Fan Shaft
9. Bearings (2)
10. Belt
11. Bearing Plate (Level 3 fans only - not shown)
1. Fan Panel
2. Propeller
3. Drive Frame Channel (2)
4. Motor Plate
5. Motor
1
1
2
2
3
5
5
8
6
7
10
9
4
3
4
