Aerovent Installation and Maintenance Manual IM-167 7
Maintenance
Installation and maintenance are to be performed only by qualified
personnel who are familiar with local codes and regulations and
experienced with this type of equipment.
Preventive maintenance is the best way to avoid unnecessary
expense and inconvenience. Routine maintenance should cover the
following items:
a. Tighten all set screws, bolts and wire connections.
b. Check belt tension and sheaves for wear.
c. Lubricatefanbearings(seeTables5and6).
d. Cleaningofunit,impelleranddamper(ifpresent).
All motors containing ball bearings are permanently lubricated
from the factory. No additional maintenance is required.
1 Beforeperforminganymaintenanceonthefan,be sure power
is turned off and locked in the OFF position at the service
entrance.
2. Fans should be carefully checked at least once a year. For
critical or rugged applications, a routine check every two or
three months is suggested.
3. For repairs within the warranty period, the motor must be
taken to the motor manufacturer’s authorized service dealer.
4. Aperiodicmotorcheckshouldconsistofspinningthemotor
shaft with the power off to be sure the motor turns freely and
the bearings run smoothly. The belt on belt driven units should
be removed from the motor sheave.
5. Whenremovingorinstallingabelt,donotforcethebeltover
thesheave.Loosenthemotormountsothatthebeltcanbe
easily slipped over the sheave.
6. Thebeltonbeltdrivenunitsshouldberemovedandcarefully
checked for glazing, cracks, ply separation or irregular wear. A
small irregularity in the contact surface of the belt will result in
noisy operation. If any of these defects are apparent, the belt
should be replaced. Check the sheaves also for chipping, dents
or rough surfaces, which could damage the belt.
7. Thecorrectbelt tension isimportant.Too tightofabeltwill
result in excess bearing pressure on the motor bearings and
shaft pillow blocks and may also overload the motor. Too loose
ofabeltwillresultinslippage,whichwillquickly“burn”out
belts.Abeltshouldfeel“live”whenthumped,approximately
1⁄4"beltdeflection(3to5lb.)whensubjecttofingerpressure
at midpoint between sheaves.
8. The belt alignment should also be checked to be sure the
beltisrunningperpendicularlytotherotatingshafts.Fanand
motor shafts must be parallel. Improper alignment will result
in excessive belt wear.
9. Checksheavesetscrewstoensuretightness.Properkeysmust
be in keyways.
10. Do not readjust fan RPM. If sheaves are replaced, use only
sheaves of identical size and type.
11. Ifunitistobeleftidleforanextendedperiod,itisrecommended
that belts be removed and stored in a cool, dry place to avoid
premature belt failure.
12. The standard pillow block bearings on belt driven fans are
factory lubricated and are provided with external grease fittings.
Lubrication annually is recommended or more frequently if
needed(seeTable5).
It is recommended to add fresh grease at start-up. Use only
2or3shotsofarecommendedlubricantwithahandgunin
mostcases (seeTable 6).Maximumhand gunrating40P.S.I.
Rotate bearings during lubrication where good safety practice
permits.
The most frequent causes of bearing failure are not
greasing often enough, using an excessive quantity of grease
or using incompatible greases. Excessive vibration, especially
if the bearing is not rotating, will also cause bearings to fail.
Bearings must also be protected from water and moisture to
avoid internal corrosion.
13. During the first fewmonths of operation it is recommended
that the bearing set screws be checked periodically to ensure
that they are tight.
14. The rotating impeller requires particular attention since
materials in the air being handled can build up on the blades
to cause destructive vibration or weaken the structure of the
impeller by corroding and/or eroding the blade metal. Regular
inspection and corrective action at intervals determined by the
severity of each application are essential to good service life
and safety.
INTERVAL TYPE OF SERVICE
(MONTHS)
12to18 Infrequentoperationorlightdutyincleanatmosphere.
6to12 8to16hrs./dayinclean,relativelydryatmosphere.
3to6 12to24hrs./day,heavyduty,orifmoistureispresent.
1to3 Heavy duty in dirty, dusty locations; high ambient
temperatures; moisture laden atmosphere; vibration.
Table 5. Suggested Fan Bearing Greasing Intervals
Table 6. Grease Manufacturers
MANUFACTURER GREASE (NLGI #2)
Shell ShellGadusS2V1002
Exxon/Mobil Ronex MP
Hazardous moving parts. Unit may contain protected fan motor,
which may start automatically and cause injury. Allow time for
reset. Disconnect power before servicing.
WARNING
Sharp edges and screws are a potential injury hazard. Avoid them.
CAUTION
Greases of different soap bases (lithium, sodium, etc.) may
not be compatible when mixed. Prevent such intermixing by
completely purging the bearing of old greases.
CAUTION
