20
Daikin
IM 777-7
Operation Guidelines
12
If multiple fans are supplied with isolation dampers,
make sure the isolation dampers are fully open before
starting the fans.
VFD Setup
Fans ordered with VFDs that were factory installed are setup
and tested prior to shipment. Prior to starting the fan(s),
double check the VFD settings according to the
recommendations in the VFD manual.
Once the correct VFD settings are verified, the fans should be
run through a sweep of the full range of operating speeds that
are expected to check for any vibration issues. If any areas of
concern are located, it is recommended to lock out those
frequencies using the VFD (see lock out frequencies or skip
frequencies in the VFD manual). This will ensure that the fans
will never operate continuously at those points, but will rather
pass through them to get to the desired points of operation.
Fan Startup
Start and run fan. See
Figure 33
for proper fan rotation.
Observe the rotation. If the fan operates backward, reverse two
legs of the three-phase motor connections.
Note:
Variable pitch fan drives usually are provided for
operation in the mid-speed adjustment range. However,
the drives usually ship with the adjustment opened up for
minimum fan speed. Adjust the drives for the proper
airflow. See
Fan Drive‚ page 26
.
After the First 48 Hours of Operation:
1
Disconnect and lock electrical power source.
2
Check tightness of all bearing, wheel, and sheave setscrews
(or capscrews). See
Table 10, page 22
.
3
Recheck belt tension and adjust if necessary. Belts that are
tensioned sufficiently to slip one to two seconds at startup
perform satisfactorily, extending life and reducing vibration. If
retensioning is necessary, be certain to retain sheave
alignment.
Fan Wheel Alignment
Figure 29: Wheel-to-Inlet Tunnel Relationship—Airfoil Type
Fan Wheels (Housed)
Note: 1. To obtain rated air performance, dimensional relationship must be
held.
2. To obtain dimension A, loosen setscrews in wheel hub(s), shifting
wheel(s) axially as needed, and retightening setscrews.
3. To obtain dimension B, loosen screw and washer fasteners around
periphery of funnel(s), shifting funnel radially as required, and re-
torquing fasteners.
Figure 30: Wheel-to-Inlet Funnel Relationship—Forward
Curved Type Fan Wheels
1.
Note: 1. To obtain rated air performance, dimensional relationship must be
held.
2. Adjust dimension C by loosening wheel hub setscrews, shifting
wheel(s) axially as needed, and retightening setscrews
Table 6: Wheel-to-Inlet Funnel Relationship—Airfoil Type
Airfoil
Unit sizes 003 to 035
Unit sizes 040 to 090
Dia.
A
(in)
A
(mm)
B
(in)
B
(mm) Dia.
A
(in)
A
(mm)
A
(in)
B
(mm)
13.22 4.56
116
0.21 5.33 20.00 7.19
183
0.31 7.87
14.56 5.06
129
0.21 5.33 22.25 7.69
195
0.33 8.38
16.18 5.62
143
0.21 5.33 24.50 8.56
217
0.31 7.87
17.69 6.90
175
0.22 5.59 27.00 9.47
241
0.63 16.00
21.56 7.59
193
0.24 6.10 30.00 10.47 266
0.39 9.91
24.00 8.45
215
0.23 5.84 33.00 11.75 298
0.38 9.65
36.50 12.78 325
0.38 9.65
40.25 14.31 363
0.50 12.70
Table 7: Wheel-to-Inlet Funnel Relationship—Forward
Curved Type Fan Wheels
Forward curved
Unit sizes 003 to 035
Unit sizes 040 to 090
Diameter (in)
C (in) C (mm)
Diameter (in)
C (in) C (mm)
9 x 4
0.25
6.35
20 (Class 1 & 2)
0.24
6.10
9 x 7
0.13
3.30 22.38 (Class 1 & 2) 0.41 10.41
9 x 9
0.25
6.35
25 (Class 1 & 2)
0.47 11.94
10
0.22
5.59 27.62 (Class 1 & 2) 0.47 11.94
12
0.35
8.89
30 (Class 1 & 2)
0.47 11.94
15
0.44 11.18
33 (Class 1 & 2)
0.50 12.70
18
0.25
6.35
36 (Class 1 & 2)
0.75 19.05
20 (Class 1 & 2)
0.73
8.54
22 1/2 (Class 1 & 2) 0.59 14.99
24 1/2 (Class 1 & 2) 0.56 14.22
A
A
B
E q u l p c n g
l l r o u n d
I n l e t
F u n n e l
W h e e l
C
C
I n l e t
F u n n e l
