COOK SRSH - Manual (Page 4)

4
For best results, lubricate the bearing while the fan is in
operation. Pump grease in slowly until a slight bead forms
around the bearing seals. Excessive grease can damage
seal and reduce life through excess contamination and/or
loss of lubricant.
In the event that the bearing cannot be seen, use no
more than three injections with a hand operated grease
gun.
Lubricants
Loren Cook Company uses petroleum lubricant in a lithium
base conforming to NLGI grade 2 consistency. Other 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 temperature
range is from -30°F to +200°F and capable of intermittent
highs of +250° F.
Motor Bearings
Motors are provided with prelubricated bearings. Any
lubrication instructions shown on the motor nameplate
supersede instructions below.
Direct Drive 1050/1075,1200,1300 &1500 rpm units use a
prelubricated sleeve bearing that has a oil saturated wick-
ing material surrounding it. The initial factory lubrication is
adequate for up to 10 years of operation under normal con-
ditions. 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 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 bear-
ings without provisions for relubrication will operate up to 10
years under normal conditions with no maintenance. In
severe applications, high temperatures or excessive con-
taminates, it is advisable to have the maintenance depart-
ment disassemble and lubricate the bearings after 3 years
of operation to prevent interruption of service.
For motors with provisions for relubrication, follow inter-
vals 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 near-
est authorized electric motor service representative.
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
Changing Shaft Speed
All belt driven ventilators (5HP or less) are equipped with
variable pitch pulleys. To change fan speed, perform the fol-
lowing:
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 lim-
its of the motor are maintained.
Replacing Pulleys and Belts
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 any grease, rust or burrs from pulleys.
f. Place the fan pulley on the fan shaft and the motor pul-
ley 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.
Belt and Pulley Installation
Belt tension is determined by the sound of the belts when
the fan is first started. The belts will produce a loud
squeal, which dissipates after the fan is operating at full
capacity. If belt tension is too tight or too loose, lost effi-
ciency and damage may occur.
a. Loosen motor plate adjustment bolts and slide motor
plate so that belts easily slip into the grooves on the pul-
leys. Never pry, roll, or force the belts over the rim of the
pulley.
b. Slide motor plate until proper tension is reached. For
proper tension, a deflection of approximately 1/4” per
foot of center distance should be obtained by firmly
pressing the belt. Refer to Figure 1.
Maximum RPM
SRSH
Size
Maximum RPM
60-100 2125
120 1715
135 1620
150 1550
165 1325
180 1535
195 1370
210 1210
225 1060
245 900
270 765