Maintenance and Repair
Core concepts
Planned maintenance systems (PMS) schedule work by running hours or calendar, with job cards, spares control, and records. A candidate must understand condition monitoring-vibration analysis, oil analysis, thermography, and performance trending-as the basis for condition-based maintenance. Know the safe work practices: permit-to-work, isolation and lockout/tagout, gas-freeing and enclosed-space entry, hot work permits, and tool and lifting safety. Understand troubleshooting logic: define the fault, gather evidence, form a hypothesis, test it, and confirm the fix.
Traps to expect
Questions test the order of safe isolation-isolate, lock/tag, prove dead, then work-and the rule that a permit is required before entry or hot work, not after. Another trap is treating vibration or oil analysis as a one-off reading rather than a trend. Spares and record-keeping questions reward knowing that maintenance history drives reliability and regulatory compliance. Distinguish preventive (scheduled) from corrective (after failure) and predictive (condition-based) maintenance.
Worked example / rule of thumb
Rising iron in lube oil analysis with stable vibration points to wear before failure-trend it, don't ignore a single sample. Rule of thumb for troubleshooting: change one variable at a time and verify the root cause before declaring repair complete. For enclosed spaces: test atmosphere, ventilate, standby person, and permit-never enter on a hunch.
Records and compliance
Maintenance records support surveys, class, and port state control. Keep job cards, spares usage, and calibration records current; a missing record can be as serious as a missing repair.