Greenheck Fan HEAT RECOVERY UNIT WITH EVAPORATIVE COOLING HRE-20 - Manual (Page 36)

36
ROUTINE MAINTENANCE
Proper fan belt settings
Belt Span
Deflection = Belt Span
64
The proper belt setting is the lowest tension
at which the belts will not slip under peak load
operation . For initial tensioning, set the belt
deflection at
1 /
64
-inch for each inch of belt span
(measured half-way between sheave centers) .
For example, if the belt span is 64 inches, the
belt deflection should be 1 inch (using moderate
thumb pressure at mid-point of the drive) . Check
belt tension two times during the first 24 hours of
operation and periodically thereafter
.
Fan Belts
Belts must be checked on a regular basis for wear, tension, alignment, and dirt accumulation . Premature
or frequent belt failures can be caused by improper belt tension (either too loose or too tight) or misaligned
sheaves . Abnormally high belt tension or drive misalignment will cause excessive bearing loads and may result
in failure of the fan and/or motor bearings . Conversely, loose belts will cause squealing on start-up, excessive
belt flutter, slippage, and overheated sheaves . Both loose and tight belts can cause fan vibration .
When replacing belts on multiple groove drives, all belts should be changed to provide uniform drive loading .
Do not pry belts on or off the sheave . Loosen belt tension until belts can be removed by simply lifting the
belts off the sheaves . After replacing belts, insure that slack in each belt is on the same side of the drive . Belt
dressing should never be used .
Do not install new belts on worn sheaves . If the sheaves have grooves worn in them, they must be replaced
before new belts are installed .
Lubrication
Check all moving components for proper lubrication . Apply lubrication where required . Any components
showing excessive wear should be replaced to maintain the integrity of the unit and ensure proper operation .
Dampers
Check all dampers to ensure they open and close properly and without binding . Backdraft dampers can be
checked by hand to determine if blades open and close freely . Apply power to motorized dampers to ensure
the actuator opens and closes the damper as designed .
Fan Motors
Motor maintenance is generally limited to cleaning and lubrication . Cleaning
should be limited to exterior surfaces only . Removing dust and grease buildup
on the motor housing assists proper motor cooling. Never wash-down motor
with high pressure spray . Greasing of motors is only intended when fittings are
provided . Many fractional motors are permanently lubricated for life and require
no further lubrication .
Fan Wheel & Fasteners
Wheels require very little attention when moving clean air . Occasionally oil and
dust may accumulate on the wheel causing imbalance . When this occurs the
wheel and housing should be cleaned to assure smooth and safe operation .
Inspect fan impeller and housing for fatigue, corrosion or wear .
Routinely check all fasteners, set screws and locking collars on the fan, bearings, drive, motor base and
accessories for tightness . A proper maintenance program will help preserve the performance and reliability
designed into the fan .