Fan Vibration Levels - Daikin Skyline OAH003GDAC Installation And Maintenance Manual

Fan Vibration Levels

Each unit as shipped is trim balanced to operate smoothly. To
provide satisfactory operation after shipping and installation,
use the accepted industry guidelines for field balancing fans.
See Table 27.
Table 27: Vibration Levels
Fan Speed (rpm)
800 or less
801 or greater
Note:
Excessive vibration from any cause contributes to premature fan and motor bearing failure.
Monitor overall vibration levels every six months of operation. An increase in levels is an
indication of potential trouble.
IM 777-18 • SKYLINE OUTDOOR AIR HANDLER
Vibration
5 mils maximum displacement
0.20 in/sec. maximum velocity
Vibration Causes
1. Wheel imbalance.
a. Dirt or debris on wheel blades.
b. Loose set screws in wheel hub or bearing-to-shaft.
c. Wheel distorted from overspeed.
2. Bent shaft.
3. Drive faulty.
a. Variable pitch sheaves—Axial and radial runout of
flanges; uneven groove spacing; out of balance.
Also similar faults in driven sheave.
b. Bad V-belts; lumpy, or mismatched; belt tension
too tight or too loose.
4. Bad bearings, loose bearing hold-down bolts
5. Motor imbalance
6. Fan section not supported evenly on foundation
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