3
MAINTENANCE
Belts tend to stretch after a period of time. They should be checked periodically for wear and tightness. When replacing
belts, use the same type as supplied with the unit. Matched belts should always be used on units with multigroove pulleys.
For belt replacement, loosen the tensioning device far enough to allow removal of the belt by hand. Do not force belts on or
off. This may cause cords to break, leading to premature belt failure. Once installed, adjust belts as shown in “Pre-Starting
Checks.”
Shaft bearings can be classified in two groups: relubricating and non-relubricating. All bearings on standard Model CUBE
fans are factory lubricated and require no further lubrication under normal use (between -20°F and 180°F in a relatively clean
environment). Units installed in hot, humid or dirty locations should be equipped with special bearings. These bearings will
require frequent lubrication. Caution should be employed to prevent overpacking or contamination. Grease fittings should be
wiped clean. The unit should be in operation while lubricating. Extreme care should be used around moving parts. Grease
should be pumped in very slowly until a slight bead forms around the seal. A high grade lithium base grease is
recommended.
Motor maintenance is generally limited to cleaning and lubrication (where applicable). Cleaning should be limited to exterior
surfaces only. Removing dust buildup on motor housing ensures proper motor cooling. Greasing of motors is only intended
when fittings are provided. Many fractional motors are permanently lubricated and should not be lubricated further. Motors
supplied with grease fittings should be greased in accordance with manufacturers’ recommendations. Where motor
temperatures do not exceed 104°F (40°C), the grease should be replaced after 2000 hours of running time as a general rule.
Wheels require very little attention when moving clean air. Occasionally, oil and dust may accumulate causing imbalance.
When this occurs, the wheel and housing should be cleaned to ensure smooth and safe operation.
The unit should be made non functional when cleaning the wheel or housing (fuses removed, disconnect locked off, etc.).
All fasteners should be checked for tightness each time maintenance checks are performed prior to restarting unit.
A proper maintenance program will help these units deliver years of dependable service.
CAUSE
CORRECTIVE ACTION
System resistance too high
Check system: Proper operation of
backdraft or control dampers,
obstruction in ductwork, etc.
Unit running backwards
Correct as shown in Fig. 3.
Excessive dirt buildup on wheels
Clean wheel.
Improper wheel alignment
Center wheel on inlets.
Bad bearings
Replace.
Belts too tight or too loose
Refer to Fig. 6 and adjust tension.
Wheel improperly aligned and
Center wheel on inlets. See Fig. 2.
rubbing
Loose drive or motor pulleys
Align and tighten. See “Pre-Starting
Checks.”
Foreign objects in wheel or
Remove objects, check for damage
housing
or unbalance.
Unbalance of wheel caused by
Remove buildup.
excessive dirt and grease buildup
REDUCED
AIRFLOW
PROBLEM
EXCESSIVE
NOISE OR
VIBRATION
TROUBLESHOOTING
NOTE: Before taking any corrective action, make certain unit is not capable of operation during repairs.
