7
Troubleshooting Guidelines
YORK
®
STACK FAN
Use safety practices when investigating fan or system performance problems. General safe practices and performance trou-
bleshooting guidelines can be found in AMCA Publication 410: Recommended Safety Practices for Users and Installers of
Industrial and Commercial Fans, and AMCA Publication 202-98 (R2011): Troubleshooting. Fan application and field mea-
surement procedures can be found in AMCA Publication 201-02 (R2011): Fans and Systems and AMCA Publication 203-90
(R2011): Field Performance Measurement of Fan Systems.
Troubleshooting Performance Problems:
The lists below indicate possible areas to check when air or sound values do not meet expectations. Most fan problems can
be pinpointed to one of these common causes.
Air Capacity Problems:
1. Air resistance of system not at design rating.
I
f air resistance is lower than expected airflow may be higher and
the associated horsepower lower. If air resistance is higher than anticipated, air volume will likely be lower.
2. Fan speed is not at design speed.
3. Air density not at design values.
Also check air performance measurement techniques / procedures.
4. Mechanical air devices
(e.g. dampers or filters), are closed or plugged.
5. Impeller mounted improperly or is rotating in reverse.
6. Parts of system or fan have been damaged or need cleaning.
Noise Problems:
1. Fan is not at design point of operation or fan is operating in an unstable flow region.
2. Bearing failure.
C
heck bearings.
3. Supply voltage high or inconsistent supply frequency. Variable frequency controllers can generate motor noise.
4. Object which are installed in a high velocity airstream can generate noise.
This includes flow sensors, turning
vanes, etc.
5. Non-uniform fan inlet conditions.
6. Acoustics or sound measurement procedure incorrect.
Vibration Problems
1. Misalignment of drive components.
2. Poor foundations (isolation base) or mounting structure (resonances).
3. Foreign object trapped in rotating components.
4. Damaged rotating components (bearings, shaft, fan, impeller).
5. Broken, loose or missing set screws.
6. Loose bolts.
7. Vibration transmitted by another source.
8. Water accumulating in airfoil blades.
9. Fan is operating in stall or unstable flow region
.
NOTE: All fans manufactured by York
®
are factory balanced
prior to shipment. Improper handling and movement of the
fan during shipment may cause the rotating assembly to shift
out of alignment Balance should be checked once the fan is
installed. If a final trim balance is required, it is the end user’s
responsibility to bring the fan back to factory specifications.
Final trim balancing is not the responsibility of York
®
.