7VA/AVA/AF IO&M B51146-004
• Periodic Applications (any break of one week or
more): it is recommended that full lubrication be per-
formed prior to each break in operation.
• Higher Temperature: it is recommended to halve the
intervals for every 30°F increase in operating tempera-
ture above 120°F not to exceed 230°F for standard bear-
ings; high temperature bearings (optional) can operate
up to 400°F.
• Vertical Shaft: it is recommended that the intervals
should be halved.
Loren Cook Company uses petroleum lubricant in a lithi-
um base. Other types of grease should not be used unless
the bearings and lines have been ushed clean. If another
type of grease is used, it should be a lithium-based grease
conforming to NLGI grade 2 consistency.
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 mainte-
nance department 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
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 month
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.
The above intervals should be reduced to half for verti-
cal shaft installations.
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 Shaft Speed
All belt driven AF fans with motors up to and including
5HP are equipped with variable pitch pulleys. To change
the fan speed, perform 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 lim-
its of the fan and the horsepower limits of the motor are
maintained.
Pulley and Belt Replacement
1. Remove pulleys from their respective shafts.
2. Clean the motor and fan shafts.
3. Clean bores of pulleys & 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 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.
7. Tighten in place.
8. Install belts on pulleys and align as described in Belt
and Pulley Installation.
Bearing Replacement
1. Loosen and remove belts by lowering motor mounting
plate with the four adjusting nuts.
2. Remove the bearing cover. Do not remove fan
sheave yet.
3. Remove prop by loosening setscrews and retaining
bolts and sliding o shaft.
4. Record the location of the fan sheave from end of
shaft, and remove the sheave.
5. Record the distance from the bearing to the end of
the shaft.
6. Loosen setscrews on bearings and remove shaft.
7. Remove bearings and replace with new bearings.
8. Slide shaft through bearings until shaft protrudes the
same amount as original shaft. Tighten setscrews.
9. Replace fan sheave in original location.
10. Replace prop but do not tighten yet.
11. Slide prop on shaft and center prop.
12. Replace and tighten belts.
13. Test run the fan.
14. Re-tighten setscrews on bearings, sheave and prop.
Recheck belt tension and adjust as needed.
15. Replace bearing cover.
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