Motor Bearings Maintenance
Routine maintenance for motor bearings should include the
following:
• Add grease to fan motors after every 2,000 hours of
operation .
• Relubricate while the motor is warm and at a standstill .
• Remove and clean upper and lower grease plugs and
insert grease fitting into upper hole, adding a small
amount of clean grease with a low pressure gun . Run the
motor for five minutes before replacing plugs.
NOTE:
Specific greasing instructions are located on a
tag attached to the motor . If special lubrication
instructions are shown on the motor nameplate, they
supersede all other instructions .
CAUTION
BEARING OVERHEATING POTENTIAL
Bearing overheating can cause damage to equipment . Do not
over lubricate . Use only a high grade mineral grease with a
200°F safe operating temperature . Refer to the unit lubrication
instruction label for specific lubricants
Table 18: Recommend Lubricants for Fan Shaft Ball
Bearings
Manufacturer
Product name
Temp . range °F (°C)
Texaco Lubricants
Company
Premium RB
-30 to 300 (-34 to 149)
Keystone Ind . Lubricants
81EP–2
0 to 250 (-18 to 121)
Mobil Oil Corporation
Mobilith SCH100
-40 to 350 (-40 to 177)
Chevron U .S .A . Inc .
SRI–2
-20 to 325 (-29 to 163)
Exxon Company, U .S .A .
Ronex MP
-40 to 300 (-40 to 149)
Shell Oil Company
Alvania No . 2
-20 to 240 (-29 to 116)
Note:
Temperature ranges over 225°F are shown for lubricants only . High
temperature applications are not suitable for standard air handler components .
Fan Bearing Maintenance
CAUTION
Failure to observe safety precautions can cause personal
injury or equipment damage .
CAUTION
Failure to carefully follow installation instructions can result in
improper installation, which can cause bearing performance
problems as well as serious personal injury . Before attempting
to install or remove bearings, read installation/removal
instructions in their entirety .
Bearings in Bolt-on Housings
(Units)
1 . Check area
• Clean and organize bearing installation area and keep
well lit .
•
Be sure mounting surfaces are clean and flat.
2 . Check shaft
• Shaft should be within tolerance range shown in
Table
19
, clean, and free of nicks and burrs .
• Mount bearing on unused section of shafting or repair/
replace shafting as required .
3 . Install unit
•
Slide bearing onto shaft. If it is difficult to mount bearing
on shaft, use a piece of emery cloth to reduce any high
spots on the shaft . Do not hammer any component of
the bearing .
4 . Fasten bearing into place
• Install housing mounting bolts, check and align bearing,
and tighten mounting bolts to recommended fastener
torques .
• Exercising extreme caution and safety, rotate shaft
slowly to center bearing .
5 . Monitor installed bearing
• After bearing has run for several minutes, and again
after several hours, check bearing for excessive noise
or vibration .
• Shut down unit and check housing temperature . Typical
applications operate at 100°F to 150°F (38°C to 66°C)
(similar to household hot tap water temperature) .
• Tighten all locking devices after 500 hours or three
months, whichever comes first.
6 . Bearing setscrew torques are shown on
Table 15 on
page 38
Table 19: Shaft tolerance range
Shaft diameter
in (mm)
Shaft tolerance
in (mm)
1/2 to 1-15/16 (12 to 49)
+0 .0 to 0 .0005 (+0 .0 to -0 .0125)
2 to 3-3/16 (50 to 80)
+0 .0 to 0 .0010 (+0 .0 to -0 .025)
3-1/4 to 4-5/16 (82 to 125)
+0 .0 to 0 .0015 (+0 .0 to -0 .040)
s
ysTem
m
aInTenanCe
www .DaikinApplied .com 43
IM 1032-2 • Self-Contained Air Conditioning Systems
