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2. MOTOR BEARINGS
Some small motors have sealed-for-life ball bearings, which require no re-lubrication.
Regreasable bearings are shipped with a high quality, wide temperature range grease in
the bearings.
NOTE: Bearings and grease must be kept free of dirt.
Bearings should be lubricated while stationary and the motor is warm. Disconnect power
to the motor (lockout/tagout). Remove the grease drain plug, if provided. Using a low
pressure grease gun, pump in the recommended grease until clean grease appears at
the grease drain, the grease relief, or along the shaft opening. Run motor for several
minutes to discharge excess grease. Replace drain plug.
New motors that have been stored for a year or more should be re-lubricated. In this
case, pump in the recommended grease until the old grease has been discharged.
Units that operate at speeds greater than 1800 RPM should be lubricated on a more
frequent maintenance schedule, depending on duty cycle.
Do not mix grease types.
Table 3: Bearing type descriptions and maintenance
SERVICE
SYMBOL
TYPE OF SERVICE
SUGGESTED MOTOR
RE-GREASING INTERVALS
A
Infrequent operation or light duty in clean
atmosphere
3-4 months
B
8-16 hrs/day in clean, relatively dry
atmosphere
4-5 days
C
12-24 hrs/day, heavy duty, or if moisture
is present
1-2 days
D
Heavy duty in dirty, dusty locations, high
ambient, vibration or moisture laden
atmosphere
Daily
RECOMMENDED MOTOR BEARING GREASES
Use the following NLGI #2 polyurea greases or equivalent grease unless special grease
is specified on the nameplate:
MANUFACTURER
TRADE NAME
Mobil
Polyrex EM
Chevron
SRI
Shell
Dolium BRB
For -30°F and below applications, contact Rocore Engineering for cold-weather or arctic
grease recommendations.
For radiators that are not operated regularly, rotate the shafts several turns, once per
month, to redistribute the grease in the bearings.