COOK Propeller Upblast - Manual (Page 5)

5
grades of grease should not be used unless the bearings
and lines have been flushed clean. If another grade of
grease is used, it should be lithium-based.
A NLGI grade 2 grease is a light viscosity, low-torque,
rust-inhibiting lubricant that is water resistant. Its tempera-
ture range is from -30
F to +200F and capable of intermit-
tent highs of +250 F.
Motor Bearings
Motor bearings are pre-lubricated and sealed. Under nor-
mal conditions they will not require further maintenance for
a period of ten years. However, it is advisable to have your
maintenance department remove and disassemble the
motor, and lubricate the bearings after three years of oper-
ation in excessive heat and or in a contaminated airstream
consisting of airborne abrasives.
Fan Bearings
Fan bearings are lubricated through a grease connector
and should be lubricated by the schedule, Conditions
Chart, on page 4.
For best results, lubricate the bearing while the fan is
rotating. Slowly pump grease into the bearing until a slight
bead forms around the bearing seals. Excessive grease
can burst seals thus reduce bearing life.
In the event the bearing cannot be seen, use no more
than three injections with a hand-operated grease gun.
Motor Services
Should the motor prove defective within a one-year
period, contact your local Loren Cook representative or
your nearest authorized electric motor service representa-
tive.
Changing Shaft Speed
All belt driven propeller roof fans with motors up to and
including 5HP are equipped with variable pitch pulleys. To
change the fan speed, perform the following:
a. Loosen setscrew on driver (motor) pulley and remove
key, if equipped.
b. Turn the pulley rim to open or close the groove facing.
If the pulley has multiple grooves, all must be adjusted
to the same width.
c. After adjustment, inspect for proper belt tension.
Speed Reduction
Open the pulley in order that the belt rides deeper in the
groove (smaller pitch diameter).
Speed Increase
Close the pulley in order that the belt rides higher in the
groove (larger pitch diameter). Ensure that the RPM limits
of the fan and the horsepower limits of the motor are main-
tained.
Maximum RPM
TUB, SUB,
SUBH
Size
Maximum
RPM
AUB
Maximum
RPM
EUB
Maximum
RPM
20 2633 24 1585 24 1650
24 1993 30 1180 30 1305
30 1605 36 1015 36 1305
36 1314 42 935 42 1200
42 1106 48 845 48 1150
48 973 54 900
54 888 60 870
60 783 72 688
72 616
Maximum RPM
TUB, SUB,
SUBH
Size
Maximum
RPM
AUB
Maximum
RPM
EUB
Maximum
RPM
20 2633 24 1585 24 1650
24 1993 30 1180 30 1305
30 1605 36 1015 36 1305
36 1314 42 935 42 1200
42 1106 48 845 48 1150
48 973 54 900
54 888 60 870
60 783 72 688
72 616
Maximum RPM
TUB, SUB,
SUBH
Size
Maximum
RPM
AUB
Maximum
RPM
EUB
Maximum
RPM
20 2633 24 1585 24 1650
24 1993 30 1180 30 1305
30 1605 36 1015 36 1305
36 1314 42 935 42 1200
42 1106 48 845 48 1150
48 973 54 900
54 888 60 870
60 783 72 688
72 616
Maximum RPM
LXUL
Size
Maximum
RPM
LXUM Maximum
RPM
LEU
Maximum
RPM
20 1270 20 1460 20 1675
24 1110 24 1400 24 1650
30 930 30 1170 30 1350
36 720 36 860 36 1310
42 600 42 718 42 1210
48 508 48 598 48 1214
54 478 54 522 54 946
60 450 60 476 60 854
Pulley and Belt Replacement
a. Clean the motor and fan shafts.
b. Loosen the motor plate mounting bolts to relieve the
belt tension. Remove the belt.
c. Loosen the pulley setscrews and remove the pulleys
from the shaft.
If excessive force is required to remove the pulleys, a
three-jaw puller can be used. This tool, however,
can easily warp a pulley. If the puller is used,
inspect the trueness of the pulley after it is
removed from the shaft. The pulley will need
replacement if it is more than 0.020 inch out of
true.
d. Clean the bores of the pulleys and place a light coat of
oil on the bores.
e. Remove grease, rust and burrs from the shaft.
f. Place fan pulley on the fan shaft and the motor pulley on
the motor shaft. Damage to the pulleys can occur when
excessive force is used in placing the pulleys on their
respective shafts.
g. After the pulleys have been correctly placed back onto
their shafts, tighten the pulley setscrews.
h. Install the belts on the pulleys. Align and adjust the
belts to the proper tension as described in Belt and Pul-
ley Installation, page 2.
Bearing Replacement
The fan bearings are pillow block ball bearings.
a. Remove the wind band and damper assembly to gain
access to the fan.
b. Loosen the motor plate mounting bolts and remove the
drive belts.
c. Remove the propeller from the shaft.
d. Remove the bearing cover. Remove the four (4) bear-
ing hold-down bolts and then remove the shaft, bear-
ings, and driven sheave from the unit as an assembly.
e. Measure and record the location of the bearings and
sheave on the shaft. This will aid the reassembly.
f. Remove the anti-corrosion coating from the shaft with a
suitable degreaser and then remove the pulley from the
shaft. An emery cloth or file may be needed to remove
imperfections in the shaft left by the setscrews.