User Manual

9
TROUBLE SHOOTING
In the event that trouble is experienced in the field, the following are the most common fan
difficulties. These points should be checked in order to prevent needless delay and expense.
A. CAPACITY OR PRESSURE BELOW RATING
1. Incorrect direction or propeller rotation
2. Speed too slow
3. Damper not properly adjusted
4. Poor fan inlet or outlet conditions (elbows, restrictions)
5. Air leaks in system
6. Damaged propeller
7. Total resistance of system higher than anticipated
8. Propeller mounted backwards on shaft
9. Fan not properly selected for a high temperature and/or high altitude application
B. VIBRATION AND NOISE
1. Misalignment of bearings, propeller or V-belt drive
2. Unstable foundation or supports
3. Worn bearings
4. Damaged propeller or motor
5. Broken or loose bolts and set screws
6. Bent shaft
7. Fan propeller or drive unbalanced
8. 120 cycle magnetic hum due to electrical input. Check for high or unbalanced voltage
9. Fan delivering more than rated capacity
10. Loose dampers
11. Speed too high or fan rotating in wrong direction
12. Vibration transmitted to fan from some other source
C. OVERHEATED BEARINGS
1. Check bearing lubrication
2. Poor alignment
3. Damage propeller or drive
4. Bent shaft
5. Abnormal end thrust
6. Dirt in bearings
7. Excessive belt tension
D. OVERLOAD ON MOTORS
1. Speed too high
2. Fan over capacity due to existing system resistance being lower than original rating
3. Specific gravity or density of gas above design value
4. Wrong direction of propeller rotation
5. Shaft bent
6. Poor belt alignment
7. Propeller wedging or binding on fan housing
8. Bearings improperly lubricated
9. Motor improperly wired
10. Defective motor. Motor must be tested by motor manufacturer's authorized repair shop