COOK LC - Manual (Page 5)

5
Direct Drive 1050/1075,1200,1300 &1500 rpm units use
a prelubricated sleeve bearing that has a oil saturated
wicking material surrounding it. The initial factory
lubrication is adequate for up to 10 years of operation
under normal conditions. However, it is advisable to add
lubricant after 3 years. Use only LIGHT grade mineral oil or
SAE 10W oil up to 30 drops. If the unit has been stored for
a year or more it is advisable to lubricate as directed above.
For direct drive units and other units in severe conditions,
lubrication intervals should be reduced to half.
Motors without sleeve bearings (as described above) will
have grease lubricated ball or roller bearings. Motor
bearings without provisions for relubrication will operate up
to 10 years under normal conditions with no maintenance.
In severe applications, high temperatures or excessive
contaminates, it is advisable to have the maintenance
department disassemble and lubricate the bearings after 3
years of operation to prevent interruption of service.
For motors with provisions for relubrication, follow
intervals of the table below.
Relubrication Intervals
Motors are provided with a polyurea mineral oil NGLI #2
grease. All additions to the motor bearings are to be with a
compatable grease such as Exxon Mobil Polyrex EM and
Chevron SRI.
The above intervals should be reduced to half for vertical
shaft installations.
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
representative.
Changing Shaft Speed
All belt driven 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
maintained.
Service
Conditions
NEMA Frame Size
Up to and
including 184T
213T-365T 404T and larger
1800
RPM
and
less
Over
1800
RPM
1800 RPM
and less
Over
1800
RPM
1800 RPM
and less
Over
1800
RPM
Standard 3 yrs. 6 months 2 yrs. 6 months 1 yr. 3 months
Severe 1 yr. 3 months 1 yr. 3 months 6 months 1 months
Maximum RPM
TLC-B
Size
Maximum RPM
HLC-B
Size
Maximum RPM
Standard Reinforced Standard Reinforced
100 1755 - 100 1740 -
120 1730 - 120 1695 -
135 1750 - 135 1780 -
150 1640 - 150 1620 -
165 1325 - 165 1335 -
180 1490 - 180 1555 -
195 1325 - 195 1345 -
210 1275 1325 210 1245 1345
225 1135 1180 225 1140 1185
245 1015 - 245 1010 -
270 865 - 270 875 -
300 830 995 300 825 985
330 700 880 330 605 865
365 610 725 365 615 705
402 535 610 402 535 615
445 455 520 445 445 510
490 390 430 490 390 430
540 345 415 540 345 415
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
Pulley Installation, page 1.
Bearing Replacement
The fan bearings are pillow block ball bearings.
a. Loosen screws on bearing cover.
b. Push bearing cover toward the wheel. As the bearing
cover moves toward the wheel it will slide down to
reveal the bearings and shaft.
c. Remove the old bearing.
d. Remove any burrs from the shaft by sanding.
e. Slide new bearings onto the shaft to the desired loca-
tion and loosely mount bearings onto the bearing sup-
port. Bearing bolts and setscrews should be loose
enough to allow shaft positioning.
f. Correctly position the wheel and tighten the bearing
bolts securely to the bearing support.