2. Remove the relief plug and clean out any
3. Add fresh grease through the fitting with a
low-pressure grease gun.
4. Run the motor for a few minutes to expel any
excess grease through the relief vent.
5. Stop the motor and replace the relief plug
Fan Bearing Lubrication
Fan bearings with grease fittings or with grease
line extensions should be lubricated with a
lithium-base grease that is free of chemical impurities.
Improper lubrication can result in early bearing failure.
To lubricate the fan bearings, complete the following:
1. Lubricate the bearings while the unit is not
running; disconnect the main power switch.
2. Connect a manual grease gun to the grease line
3. Add grease, preferably when the bearing is
warm, while turning the fan wheel manually
until a light bead of grease appears at the bearing
To clean permanent filters, wash under a stream of
hot water to remove dirt and lint. Follow with a wash
of mild alkali solution to remove old filter oil. Rinse
thoroughly and let dry. Recoat both sides of the filter
with filter oil and let dry. Replace the filter element in
Always install filters with directional
arrows pointing toward the fans.
Perform all of the indicated maintenance
procedures at the intervals scheduled. This prolongs
the life of the unit and reduces the possibility of costly
equipment failure and downtime. A checklist should
be prepared which lists the required service operations
and the times at which they are to be performed. The
following is a sample of such a list.
1. Check the compressor oil level. If low, allow
the compressor to operate continually at full load for 3
to 4 hours; check the oil level at 30-minute intervals. If
the level remains low, add oil.
2. Observe the oil pressure. The oil pressure gauge
reading should be approximately 20 to 35 psi above the
suction pressure gauge reading.
3. Stop the compressor and check the shaft seal for
excessive oil leakage. If found, check the seal with a
refrigerant leak detector (open compressor only).
4. Check the condition of the air filters and
air-handling equipment. Clean or replace filters, as
5. Check the general operating conditions, system
pressures, refrigerant sight glass, and so forth.
(Repeat Items 1 through 5)
6. Lubricate the fan and motor bearings, as
Obtain and follow the manufacturers
lubricant specifications and bearing care instructions.
7. Check the fan belt tension and alignment.
8. Tighten all fan sheaves and pulleys. If found to
be loose, check alignment before tightening.
9. Check the condition of the condensing
equipment. Observe the condition of the condenser coil
in the air-cooled condenser. Clean, as necessary. Check
the cooling tower water in the water-cooled condenser.
If algae or scaling is evident, water treatment is needed.
Clean the sump strainer screen of the cooling tower.
(Repeat Items 1 through 9)
10. Drain all circuits of the water-condensing
system. Inspect the condenser piping and clean any
scale or sludge from the tubes of the condenser.
11. If a cooling tower or evaporative condenser is
used, flush the pumps and sump tank. Remove any rust
or corrosion from the metal surfaces and repaint.
12. Inspect all motor and fan shaft bearings for signs
of wear. Check the shafts for proper end-play