Carrier AERO 39MN Installation, Start-Up And Service Instructions Manual page 123

Example:
Fan RPM =
=
Refer to Table 3B for maximum allowable fan speeds
for fan wheels. Excessive fan speed may result in con-
densate carryover from cooling coil or fan motor over-
load and wheel failure.
8. Check direction of rotation (see Fig. 80). Arrow on
drive side of fan housing indicates correct direction of
rotation.
CAUTION
Drive ratios of 1:1 may cause excessive vibration. Avoid if
possible.
9. Check vibration. If excessive vibration occurs, check for
the following:
a. Variable sheave (if air balance of system has been
accomplished; replace sheave with fixed sheave for
continuous application).
b. Drive misalignment.
c. Mismatched, worn, or loose belts.
d. Wheel or sheaves loose on shaft.
e. Loose bearings.
f. Loose mounting bolts.
g. Motor out of balance.
h. Sheaves eccentric or out of balance.
i. Vibration isolators improperly adjusted.
j. Out-of-balance or corroded wheel (rebalance or
replace if necessary).
k. Accumulation of material on wheel (remove excess
material).
DRIVE PULLEY
NOMINAL
SCREW SIZE
No. 6
No. 8
No. 10
1
/
4
5
/
16
3
/
8
Fig. 106 — Fan, Shaft and Bearing Details — Roller
— Extended Race, One or Both Sides
Actual Approximate
1760 x 8.9 1760 x 9.0
12.4 12.5
1263 RPM = 1267 RPM
a39-2047
TORQUE
(in.-lb)
9
16
30
70
140
216
CAPSCREW AND
SETSCREW
SIZE (No./in.)
10
1
/
4
5
/
16
3
/
8
7
/
16
1 /
2
5 /
8
3 /
4
BEARING HOLDDOWN BOLT TORQUE
BOLT SIZE (in.)
3 / - 16
8
1 / - 13
2
5
/ - 11
8
3
/ - 10
4
Fig. 107 — Fan, Shaft and Bearing Details —
Squeeze-Type Locking Collar
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 or fans described above with the follow-
ing additions:
1. Check tightness of bolts securing fan motor to base.
2. Check tightness of fan wheel bushing bolts (see Fig. 108)
per table below.
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. 108) is
within limits per following table.
122
a39-2048
TORQUE TABLE
HEX HEAD SQUARE HD
ACROSS ACROSS
FLATS (in.) FLATS (in.)
3 / —
32
1
/ —
8
5
/ —
32
3
/ —
16
7
/ —
32
1 / 1 /
4 2
5 / —
16
3 / —
8
TORQUE (ft-lb)
30
63
100
165
TORQUE (in.-lb)
72
108
180
360
TORQUE
25 in.-lb
60 in.-lb
10 ft-lb
17 ft-lb
25 ft-lb
40 ft-lb
90 ft-lb
125 ft-lb
procedures