Generator Set Maintenance Flashcards

What is the primary reason for performing a coolant analysis as part of a generator set preventive maintenance program?

Answer: To monitor glycol concentration, pH, corrosion inhibitor depletion, and contaminant levels before failures occur

Coolant analysis detects depleted corrosion inhibitors and contamination that would otherwise cause internal corrosion and premature cooling system component failure.

A generator set produces normal voltage at no load but the voltage collapses significantly under full load. Which component is most likely the cause?

Answer: Weak excitation from a faulty AVR or under-sized exciter winding capacity

Voltage collapse under load is a classic sign that the excitation system cannot supply adequate reactive power, indicating AVR, exciter winding, or PMG failure.

During maintenance, a technician finds that the fuel day tank low-level alarm activates correctly but the automatic fill pump does not start. What is the first component to check?

Answer: The fill pump control relay or float switch wiring continuity

When an alarm activates correctly but the associated pump fails to start, the control circuit between the alarm and pump — typically a relay or wiring connection — is the first suspect.

What is the correct action when the oil analysis report shows a significant increase in iron (Fe) content compared to the previous sample interval?

Answer: Investigate for accelerated internal engine wear and schedule an inspection before the next planned service

A rising iron trend in oil analysis indicates abnormal wear of ferrous engine components such as cylinder liners, piston rings, or crankshaft, requiring immediate investigation.

What maintenance procedure helps prevent starting system failure caused by diesel fuel gelling in cold weather operation?

Answer: Using winter-blend fuel with appropriate CFPP rating and installing engine block heaters

Winter-blend diesel with a Cold Filter Plugging Point (CFPP) appropriate for ambient temperature, combined with block heaters, prevents fuel gelling and ensures reliable cold-weather starting.

When conducting a generator set maintenance inspection after a fault trip on overcurrent, which component should be inspected for signs of damage before resetting and restarting?

Answer: Alternator windings, connections, and circuit breaker contacts for signs of overheating or arcing

An overcurrent fault can cause thermal damage to alternator windings and arc erosion on breaker contacts; these must be inspected before returning the unit to service.

What does the EGSA maintenance standard recommend regarding documentation of generator set maintenance activities?

Answer: Comprehensive written maintenance records should be kept to track service history, trends, and support warranty claims

EGSA standards emphasize maintaining comprehensive written service records to enable trend analysis, verify warranty compliance, and support reliable long-term operation of generating equipment.