McQuay Skyline IM 777-1, Руководство по установке и обслуживанию

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McQuay IM 777-1 19
Operation Guidelines
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 10.
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.
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
Table 10: Vibration levels
Fan speed (rpm) Vibration
800 or less 5 mils maximum displacement
801 or greater 0.20 in/sec. maximum velocity
Table 11: Operating limits—inline fans, twin fans
Fan operating limits
Inline fans
Diameter 18.25 20 22.25 24.5 27 30 33 36.5 40.25 44.50 49 54.25
Maximum rpm Class I 2727 2488 2236 2041 1835 1665 1476 1330 1208 1072 973 880
Maximum rpm Class II 3409 3111 2796 2551 2294 2082 1846 1662 1510 1340 1216 1100
Twin fans
Diameter 9 x 9 10.62 12.62 15 18.12 20
Maximum rpm 2575 2400 2000 1700 1400 1200
Maximum HP 10 15 15 30 40 40