McQuay Skyline IM777, Installation And Maintenance Manual

Page: 16 / 28

Page 16 IM777
Fan Operating Limits
Do not exceed the operating limits in Table 7. A fan wheel that
is operated beyond the rpm limits shown may suffer permanent
distortion or fracture. The resulting unbalance may cause
severe unit vibration.
Table 7: Operating limits - housed fans
Figure 22. Torque for FC variable inlet vanes (in. - lb.) Figure 23. Torque for AF variable inlet vanes (in. - lb.)
Table 8: Operating limits — plenum fans
FAN OPERATING LIMITS
Forward curved — Housed
Diameter 9 x 4 9 x 7 9 x 9 10.62 12.62 15 18 20 22.25 24.50
Maximum RPM Class I N/A 2189 2223 1934 1614 1328 1155 1050 944 858
Maximum RPM Class II 2244 2854 2896 2518 2091 1725 1450 1200 1030 910
Airfoil — Housed
Diameter 13.22 14.56 16.19 19.69 21.56 24.00
Maximum RPM Class I 3000 3000 2300 2000 1700 1500
Maximum RPM Class Il 4335 3918 3457 2858 2547 2255
FC24.50
300
250
200
150
100
90
80
70
60
50
T
orque (in.-lb.)
Fan Speed (rpm)
800 850 900
1000
1500 2000
400 500 600 700 350 450 550 650 750
FC22.25
FC20.00
FC18.00
FC15.00
FC12.62
3 0 0
2 5 0
2 0 0
1 5 0
1 0 0
9 0
8 0
7 0
6 0
5 0
75
0
80
0
85
0
90
0
10
00
15
00
20
00
F a n S p e e d ( r p m )
4 0
3 5
3 0
A F
2 4
. 0 0
A F
2 1
. 5 6
A F
1 9
. 6 9
A F
1 6
. 1 9
A F
1 4
. 5 6
A F
1 3
. 2 2
25
00
30
00
35
00
40
00
45
00
3 5 0
4 0 0
4 5 0
To
rq
ue
(i
n.
-
lb
.)
FAN OPERATING LIMITS
Diameter 13.5 15 16.5 18.25 20 22.25 24.5 27 30 33 36.5 40.25
Maximum RPM Class I 2895 2589 2376 2256 2077 1875 1691 1479 1328 1209 1073 972
Maximum RPM Class II 3786 3384 3100 2959 2703 2413 2199 1928 1730 1579 1401 1264
Maximum RPM Class III 4000 4000 3887 3735 3409 3065 2780 2423 2182 1984 1756 1598