Two, Four, Or Six-Fan Array Direct Drive - Carrier Aero 39MN Series Installation, Start-Up And Service Instructions Manual

BELT DRIVE PLENUM FANS — Start-up procedures for
plenum fans are similar to those for airfoil or forward-curved
fans described in the preceding section. Also refer to the fan
manufacturer's Installation, Operation, and Maintenance in-
structions shipped with the plenum fan section for further
details.
DIRECT DRIVE PLENUM FANS — Start-up
are similar to those for fans described above with the following
additions:
1. Check tightness of bolts securing fan motor to base.
2. Check tightness of fan wheel bushing bolts (see Fig. 157)
per Table 44 below.
Table 44 — Bushing Bolt Torque
BUSHING TYPE
JA
SD
SK
SF
3. Visually verify the radial clearance between the fan wheel
and the inlet cone is equal in all directions.
4. Verify the fan wheel to inlet cone overlap (see Fig. 157) is
within limits per Table 45 below.
5. Turn the fan wheel by hand to ensure no contact with inlet
cone.
6. If provided with piezometer ring, verify all tubing con-
nections are secure.
Table 45 — Inlet Cone Overlap
WHEEL SIZE
105
122
135
150
165
182
200
222
245
270
300
330
365
402
7. Ensure VFD has been programmed with the correct max-
imum fan speed and maximum output frequency to limit
motor speed (rpm) to fan maximum speed (rpm).
a. See label on fan sled for maximum fan speed
(rpm).
b. Check VFD for maximum fan speed (parameter
2002) to ensure that the fan maximum speed is the
VFD maximum speed.
c. Using the Parameters Mode (page 150) on the
VFD, verify that parameter 2002 has been changed
to the value shown on the fan label. If it does not
match, DO NOT start the unit. Press Edit (Soft
Key 2) to enter correct value for parameter 2002.
Press Exit (Soft Key 1).
d. See motor nameplate for operating frequency (Hz)
and speed (rpm).
procedures
TORQUE (in.-lb)
72
108
180
360
WHEEL - CONE OVERLAP (in.)
0.12 - 0.29
0.12 - 0.32
0.12 - 0.34
0.19 - 0.41
0.25 - 0.47
0.31 - 0.50
0.38 - 0.57
0.44 - 0.63
0.50 - 0.69
0.56 - 0.76
0.62 - 0.88
0.75 - 0.96
0.81 - 1.13
0.88 - 1.26
WHEEL OVERLAP
a39-4388
Fig. 157 — Fan Wheel Bushing Location
e. VFD maximum frequency setpoint (parameter
2008) = motor frequency (Hz) * fan max speed
(rpm) / motor nominal operating speed (rpm).
Example:
Motor Frequency = 60 Hz
Fan Max Speed = 2979 RPM
Motor Nominal Operating Speed = 1760 RPM
Max Frequency Setpoint = 60 Hz * 2979 RPM /
1760 RPM = 101 Hz
f. Using the Parameters Mode (page 150) on the
VFD, verify that parameter 2008 has been changed
to the calculated value. If it does not match, DO
NOT start the unit. Press Edit (Soft Key 2) to enter
correct value for parameter 2008. Press Exit (Soft
Key 1).

TWO, FOUR, OR SIX-FAN ARRAY DIRECT DRIVE

PLENUM FANS — Start-up procedures for 2, 4 or 6-fan ar-
rays are similar to those for single direct-drive fans as de-
scribed in the previous sections, with the following additions:
1. Start-up procedures must be completed for all fans.
2. If VFD(s) is mounted on fan bulkhead panel at a shipping
split, then the VFD remote keypad assembly is shipped
inside the fan section. See Fig. 158.
a. Install bracket with keypad by removing an exist-
ing screw from the cover on the vertical frame on
the mating section, taking care to avoid all door
latch areas.
b. Position bracket so VFD remote keypad is upright
and attach bracket by re-installing the removed
screw.
c. Plug VFD extension cable into the remote keypad
and the VFD.
d. Coil excess cable, secure with wire tie, and route
cable away from fan inlet. Secure with wire ties
and screws.
3. If each motor is controlled by a single VFD, then start-up
procedures must be performed for each VFD.
178
FAN WHEEL
BUSHING BOLTS