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Shaft and Bearings
Daily Check bearing temperature, lubrication, and oil level. (See FIST Volume 2-4,
Lubrication of Powerplant Equipment.)
Lubrication of Powerplant Equipment.)
During Shutdown/Inspection Check bearing clearances. Check oil for dirt, sludge,
and acidity, and filter or replace as necessary. Check end play on horizontal machines.
Replace or refinish rough bearings. Inspect bearing oil piping and cooling water piping
for leaks. Check shaft for wobble and alignment. Check for shaft currents through
bearings on larger machines. Check insulation of insulated bearings. Check oil film
resistance occasionally with machine in operation with ohmmeter of 6 volts or less on
thrust bearings provided with test terminals.
and acidity, and filter or replace as necessary. Check end play on horizontal machines.
Replace or refinish rough bearings. Inspect bearing oil piping and cooling water piping
for leaks. Check shaft for wobble and alignment. Check for shaft currents through
bearings on larger machines. Check insulation of insulated bearings. Check oil film
resistance occasionally with machine in operation with ohmmeter of 6 volts or less on
thrust bearings provided with test terminals.
Couplings, Gears, and Pulleys
* See that keys, setscrews, and coupling bolts are tight. Check parts of flexible
couplings for wear or fatigue. Adust belt or silent chain tension. Flush out and renew
grease in gearboxes. Inspect belts, chains, or gears. Check alignment between driving
and driven machine.
couplings for wear or fatigue. Adust belt or silent chain tension. Flush out and renew
grease in gearboxes. Inspect belts, chains, or gears. Check alignment between driving
and driven machine.
Cooling Coils and Air Coolers
* Check for water leaks in bearing cooling coils and surface air coolers. Check cooling
water flow. Check external supply and piping for leaks. Flush out cooling coils with
air and water. Test bearing cooling coils for leaks by applying air pressure to coils
and observe for air bubbles rising in oil and drop in air pressure with supply valve
closed, or use hydrostatic pressure test. Use hydrostatic pressure test on air coolers.
If water scale is present, circulate a solution of 25-percent hydrochloric acid and
water through the coils until clean. Then flush out thoroughly. Clean external
surfaces of coils if practical. A pressure of 75 pounds per square inch is
recommended.
air and water. Test bearing cooling coils for leaks by applying air pressure to coils
and observe for air bubbles rising in oil and drop in air pressure with supply valve
closed, or use hydrostatic pressure test. Use hydrostatic pressure test on air coolers.
If water scale is present, circulate a solution of 25-percent hydrochloric acid and
water through the coils until clean. Then flush out thoroughly. Clean external
surfaces of coils if practical. A pressure of 75 pounds per square inch is
recommended.
Temperature Indicators and Relays, Water and Oil Flow, and
Pressure Gages and Relays
Pressure Gages and Relays
* Check indicators, gages, and relays for correct operation and sticking, dirty contacts.
Check calibration if in doubt.
Recordkeeping
Maintain detailed records tracking armature temperature against generator load. If
temperature readings begin to rise over 5 degrees Centigrade for the same loading
conditions, this may indicate a problem that should be investigated.
temperature readings begin to rise over 5 degrees Centigrade for the same loading
conditions, this may indicate a problem that should be investigated.
References
How to Maintain Electric Equipment, GET-1125, General Electric Company
FIST Volume 1-4, Permissible Loading of Generators and Large Motors
FIST Volume 2-2, Field Balancing of Large Rotating Equipment
FIST Volume 1-4, Permissible Loading of Generators and Large Motors
FIST Volume 2-2, Field Balancing of Large Rotating Equipment