Emerson 986269, LARGE AC ELECTRIC MOTORS manual XI. Lubrication

U.S. ELECTRICAL MOTORS INSTALLATION AND MAINTENANCE

Lubrication

E.Reassemble motor by reversing the disassembly procedure in Section IX “Disassembly”. Bearings should be installed per bearing manufacturer's recommended procedure. Pack bearings with grease per Section XI "Lubrication".

F.Torque bolts per values in Table 4.

G.Touch up any scratched or chipped paint to protect motor surfaces.

XI. LUBRICATION

A.Relubrication of Units in Service

Units with grease lubricated bearings are pre-lubricated at the factory and normally do not require initial lubrication. Relubricating interval depends upon speed, type of bearing and service. Refer to Table 2 for suggested regreasing intervals. Note that operating environment and application may dictate more frequent lubrication.

Motor must be at rest and electrical controls should be locked open to prevent energizing while motor is being serviced (Refer to section on Safety, page i). If motor is being taken out of storage, refer to Section III "Storage". Part 4, for preparation instructions.

To relubricate bearings, remove the drain plug. Inspect grease drain and remove any blockage (caked grease or foreign particles) with a mechanical probe or scavenger (take care not to damage bearing). Under NO circumstances should a mechanical probe or scavenger be used while the motor is in operation. Add new grease at the grease inlet. New grease must be compatible with grease already in the motor (refer to Tables 2 and 3 for compatible greases and replenishment quantities).

CAUTION

Greases of different bases (lithium, polyurea, clay, etc.) may not be compatible when mixed. Mixing such greases can result in reduced lubricant life and premature bearing failure. Prevent such intermixing by disassembling motor, removing all old grease and repacking with new grease per Item B of this section. (Refer to Table 3 for recommended grease).

Run the motor for 15 to 30 minutes with the drain plug removed to allow purging of any excess grease (to eliminate the possibility of overgreasing). Shut off unit and replace the drain plug. Put motor back into operation.

CAUTION

Overgreasing can cause excessive bearing temperatures, premature lubricant breakdown and bearing failure. Care should be exercised against overgreasing.

B.Change of Lubricant:

Motor must be disassembled as outlined in Section IX "Disassembly".

Remove all old grease from bearings and housings (including all grease fill and drain holes). Inspect and replace damaged bearings. Fill bearing housings both inboard and outboard of bearing approximately 30 percent full of new grease. Grease fill fittings should be fully charged with new grease. Inject new grease into bearing between rolling elements to fill bearing. Remove any excess grease extending beyond the edges of the bearing races and retainers.

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