4
ACSC IO&M
B51002-002
Motor Services
Should the motor prove defective within a one-year pe-
riod, contact your local Loren Cook representative or your
nearest authorized electric motor service representative.
Maximum RPM
ACSC
HP Size
Maximum RPM
Standard Reinforced
150
1952
-
165
1728
-
180
1829
-
195
1570
-
210
1626
-
225
1435
-
245
1185
1234
270
1025
1049
300
980
1046
330
830
912
365
735
872
ACSC-XP Size Maximum RPM
165
2508
180
2396
195
2100
210
2126
225
1879
245
1616
270
1656
300
1391
330
1182
365
1132
Changing Shaft Speed
All belt driven ventilators (5HP or less) are equipped with
variable pitch pulleys. To change fan speed, per-form the
following:
1. Loosen setscrew on driver (motor) pulley and remove
key, if equipped.
2. 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.
3. 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
1. Clean the motor and fan shafts.
2. Loosen the motor plate mounting bolts to relieve the belt
tension. Remove the belt.
3. 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.
4. Clean the bores of the pulleys and place a light coat of oil
on the bores.
5. Remove any grease, rust or burrs from pulleys.
6. Place the fan pulley on the fan shaft and the motor pulley on
the motor shaft. Damage to the pulleys can occur when ex-
cessive force is used in placing the pulleys on their respec-
tive shafts.
7. After the pulleys have been correctly placed back onto their
shafts, tighten the pulley setscrews.
Bearing Replacement
The fan bearings are pillow block type ball bearings.
1. Remove the old bearing.
2. Remove any burrs from the shaft by sanding.
3. Slide new bearings onto the shaft to the desired lo-
cation and loosely mount bearings onto the bearing
support. Bearing bolts and setscrews should be loose
enough to allow shaft positioning.
4. Correctly position the wheel and tighten the bearing
bolts securely to the bearing support.
Maintenance
Fan Bearings
NOTICE! The fan bearings are provided prelubri-
cated. Any specialized lubrication instructions on
fan labels supersedes information provided here-
in. Bearing grease is a petroleum lubricant in a
lithium base conforming to an NLGI #2 consisten
-
cy. If user desires to utilize another type of lubri-
cant, they take responsibility for flushing bearings
and lines, and maintaining a lubricant that is com-
patible with the installation.
An NLGI #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.
Conditions Chart
RPM
Temp °F
Greasing Interval
Up to 1000
-30 to 120
6 months
120 to 200
2 months
1000 to 3000
-30 to 120
3 months
120 to 200
1 month
Over 3000
-30 to 120
1 month
120 to 200
2 weeks
Any Speed
< -30
Consult Factory
Any Speed
> 200
1 week
For moist or otherwise contaminated installations; divide the interval by
a factor of three. For vertical shaft installations divide the interval by a
factor of two.
Bearings should be relubricated in accordance with the
condition chart above.
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.
Motor Bearings
Motors are provided with prelubricated bearings. Any lu-
brication instructions shown on the motor nameplate su-
persede instructions below.
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 main-
tenance department disassemble and lubricate the bear-
ings after three years of operation to prevent interruption
of service. For motors with provisions for relubrication, fol-
low intervals of the table below.
Relubrication Intervals
Service
Conditions
NEMA Frame Size
Up to and
Including 184T
213T-365T
404T and Larger
1800
RPM &
Less
Over
1800
RPM
1800
RPM &
Less
Over
1800
RPM
1800
RPM &
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 month
NOTICE! Motors are provided with a polyurea min-
eral oil NGLI #2 grease. All additions to the motor
bearings are to be with a compatible grease such
as Exxon Mobil Polyrex EM and Chevron SRI.
The above intervals should be reduced to half for verti-
cal shaft installations.