COOK CFS - Manual (Page 6)

6
For motors with provisions for relubrication, follow inter-
vals of the table below.
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.
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 fans with motors up to and including 5 HP
(184T max.) 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.
Pulley and Belt Replacement
a. Remove pulleys from their respective shafts.
b. Clean the motor and fan shafts.
c. Clean bores of pulleys and coat the bores with heavy
oil.
d. Remove grease, rust, or burrs from the pulleys and
shafts.
e. Remove burrs from shaft by sanding.
f. Place fan pulley on fan shaft and motor pulley on its
Relubrication Intervals
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
shaft. Damage to the pulleys can occur when exces-
sive force is used in placing the pulleys on their
respective shafts.
g. Tighten in place.
h. Install belts on pulleys and align as described in the
Belt and Pulley Installation section.
Bearing Replacement
The fan bearings are pillow block ball bearings. Bearings
should be replaced individually for each side of fan.
An emery cloth or file may be needed to remove imper-
fections in the shaft left by the setscrews.
a. Remove belts.
b. If replacing drive side bearing, mark location of pulley
and remove.
c. Mark bearing location on bearing support and loosen
bearing hold-down bolts.
d. Support shaft to remove weight from bearing.
e. Remove anti-corrosion coating from the shaft with a
suitable degreaser.
f. Remove the bearing from the shaft using a bearing
puller. If a bearing puller is not available, tap on the
bearing with a wood block and hammer to remove it.
g. Remove the bearing from the shaft using a bearing
puller. If a bearing puller is not available, tap on the
bearing with a wood block and hammer to remove it.
h. Smooth and clean the shaft and bearing bore thor-
oughly.
i. Place the bearings into position making sure they are
not on a worn section of the shaft. Tapping the inner
ring face with a soft driver may be required. Do not
hammer on the housing.
j. The outer ring of the bearing is spherical and swivels in
the housing to compensate for misalignment. Secure
hold-down bolts, but do not fully tighten.
k. Align the setscrews on the bearings and tighten one
setscrew on each bearing.
l. Rotate the shaft to allow the bearing outer rings to find
their center of free movement.
m. Tighten hold-down bolts to proper torque.
n. Turn the shaft by hand. Resistance should be the
same as it was before hold-down bolts were fully tight-
ened.
o. Tighten bearing setscrews to specified torque. Refer
to Torque chart.
p. Re-install the pulley and adjust the belt tension.
q. Repeat process for opposite bearing.
r. Test run the fan and trim the balance as necessary
(.0785 in/sec max.).
s. Retighten setscrews on bearings, sheave, and wheel.
Recheck belt tension and adjust as needed.
Speed Limit Table
CFS Sizes Speed Limit
120 3,714
135 3,307
150 2,751
165 2,374
180 2,176
195 2,009
210 1,865
225 1,741
245 1,631
270 1,443
300 1,262
330 1,147
365 1,038