7SQN IO&M B51141-004
Motor Bearings
Motors are provided with prelubricated bearings. Any lu-
brication instructions shown on the motor nameplate su-
persede instructions below.
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 lubrica-
tion is adequate for up to 10 years of operation under nor-
mal 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 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 following table.
Relubrication Intervals
Service
Conditions
NEMA Frame Size
Up to & including
184T
213T-365T 404T & larger
1800
RPM and
less
Over
1800
RPM
1800
RPM and
less
Over
1800
RPM
1800
RPM and
less
Over
1800
RPM
Standard 3 years 6 months 2 years 6 months 1 year 3 months
Severe 1 year 3 months 1 year 3 months 6 months 1 months
The above intervals should be reduced to half for vertical shaft
installations.
Motors are provided with a polyurea mineral 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.
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.
Changing Fan Speed
All belt driven fans with motors up to and including 5 HP
are equipped with variable pitch pulleys.
1. Loosen setscrew on motor pulley
2. Open or close the groove facing to change the pitch
diameter.
• Speed Reduction: Open the pulley in order that the
belt rests deeper in the groove.
• Speed Increase: Close the pulley in order that the
belt rests higher in the groove. Ensure RPM limits of
the fan and the horsepower limits of the motor are
maintained.
3. Retighten pulley setscrew on one of the at areas of
the motor shaft.
4. After the adjustment is made, check for proper belt
tension. See Belt and Pulley Installation.
Maximum RPM
SQN-B Size
Maximum RPM
Non-Reinforced Wheel Reinforced Wheel
60 3795 -
70 4006 -
80 3409 -
100 3243 -
120 2867 -
135 2332 -
150 2099 -
165 1833 2107
180 1610 1786
195 1429 1593
210 1277 1399
225 1152 1459
245 1015 1434
270 876 1226
300 837 1024
330 716 962
365 624 786
402 539 683
SQN-HP Size
Maximum RPM
Non Reinforced Wheel Reinforced Wheel
135 2622 -
150 2929 -
165 2635 -
180 2169 -
195 1955 -
210 1781 -
225 1500 1861
245 1185 1773
270 1025 1563
300 980 1204
330 830 1178
365 735 1038
402 630 970
Bearing Cover Screws
(Several screws on opposite side
not shown in photograph.)
Bearing Cover
Pulley and Belt Replacement
1. Remove pulleys from their respective shafts.
2. Clean the motor and fan shafts.
3. Clean bores of pulleys and coat the bores with heavy oil.
4. Remove grease, rust, or burrs from the pulleys and
shafts.
5. Remove burrs from shaft by sanding.
6. Place fan pulley on fan shaft and motor pulley on its
shaft.
NOTICE! Do not hammer the pulleys onto the shafts
because this may damage the bearings.
7. Tighten in place.
8. Install belts on pulleys and align as described in Belt
and Pulley Installation.
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