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8. Bearings
Daily. Check the bearing temperature and lubricant level. Check flow and pressure of cooling water.
Check flow and pressure of turbine guide bearing oil pump.
Check flow and pressure of turbine guide bearing oil pump.
Annual. Take oil sample from all bearings, preferably while unit is running some time before a scheduled
outage. If it is not possible to obtain samples with unit running, samples should be taken immediately after
shutdown while the oil is still hot. The viscosity, acidity, and water content of the samples should be
checked as a minimum. The oil may also be checked for the presence of wear particles or other
contaminants. Based on the results of the oil tests, the oil should be drained and filtered.
outage. If it is not possible to obtain samples with unit running, samples should be taken immediately after
shutdown while the oil is still hot. The viscosity, acidity, and water content of the samples should be
checked as a minimum. The oil may also be checked for the presence of wear particles or other
contaminants. Based on the results of the oil tests, the oil should be drained and filtered.
Check bearing clearances with dial indicators and by "jacking" the shaft or with feeler gauges. Any change
in previous readings should be investigated. Calibrate temperature sensors and oil level indicators. Check
operation of alternating current (AC) and DC turbine guide bearing and thrust bearing high pressure
lubrication system oil pumps. Note operating pressure of high pressure lubrication system and investigate
if it is significantly different from previous readings. Check filters on high pressure lubrication system and
clean or replace as required.
in previous readings should be investigated. Calibrate temperature sensors and oil level indicators. Check
operation of alternating current (AC) and DC turbine guide bearing and thrust bearing high pressure
lubrication system oil pumps. Note operating pressure of high pressure lubrication system and investigate
if it is significantly different from previous readings. Check filters on high pressure lubrication system and
clean or replace as required.
Check the generator thrust bearing and upper guide bearing insulation with an ohmmeter
following the procedure in FIST,
following the procedure in FIST,
Volume 3-11, Generator Thrust Bearing Insulation and Oil
Film Resistance
. If resistance is low, investigate cause immediately.
Not Scheduled. Remove bearings and check for any damage. Light scoring and other minor damage can
be removed by scraping babbitt bearings. If there is severe damage to the babbitt surface, the bearing
should be rebabbitted.
be removed by scraping babbitt bearings. If there is severe damage to the babbitt surface, the bearing
should be rebabbitted.
Remove cooling coils and clean out any deposits. Hydrostatic test coils for several hours to check for leaks
before reinstalling. Check normally inaccessible portions of the thrust bearing high pressure lubrication
system for leaks or broken hoses.
before reinstalling. Check normally inaccessible portions of the thrust bearing high pressure lubrication
system for leaks or broken hoses.
9. Shaft and Coupling
Annual. Check shaft runout with dial indicator or with proximity probes and a strip chart recorder. At
minimum, check runout at full load, and if possible, record the runout as the unit is loaded from speed-no-
load to full load. Make note of the maximum runout magnitude and the load at which it occurred.
Investigate if runout is excessive or has changed significantly from previous readings.
minimum, check runout at full load, and if possible, record the runout as the unit is loaded from speed-no-
load to full load. Make note of the maximum runout magnitude and the load at which it occurred.
Investigate if runout is excessive or has changed significantly from previous readings.
10. Generator or Motor
Annual. Thoroughly inspect stress carrying parts of rotor for cracks. Pay particular attention to welds on
the rotor spider. Any cracks should be evaluated by engineering personnel, and a repair procedure.
developed. Check bolted connections for tightness and any evidence of movement. Check stator frame for
loose connections, cracks, or other damage. Check stator air gap at a minimum of four positions, top, and
bottom.
the rotor spider. Any cracks should be evaluated by engineering personnel, and a repair procedure.
developed. Check bolted connections for tightness and any evidence of movement. Check stator frame for
loose connections, cracks, or other damage. Check stator air gap at a minimum of four positions, top, and
bottom.