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. Bearings on sizes 80 through 180
are factory lubricated and require no further lubrication under normal use (between -20°F and 180°F in a relatively clean
environment). Bearings on size 200 are relubricatable. 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 the manufacturer’s recommendations. Where motor
temperatures do not exceed 104ºF (40ºC), 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.
3
TROUBLESHOOTING
NOTE: Before taking any corrective action, make certain unit is not capable of operation during repairs.
PROBLEM
CAUSE
CORRECTIVE ACTION
Reduced
Airfl ow
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. 4
Excessive dirt buildup on wheels
Clean wheel
Improper wheel alignment
Center wheel on inlets
Excessive Noise
or Vibration
Bad bearings
Replace
Belts too tight or too loose
Refer to Fig. 6 and adjust tension
Loose drive or motor pulleys
Align and tighten. See “Pre-Starting
Checks”
Foreign objects in wheel or housing
Remove objects, check for damage or
unbalance
Unbalance of wheel caused by excessive
dirt and grease buildup
Remove buildup
