EGSA System Troubleshooting and Maintenance 2

Question 1

A generator set shows high coolant temperature alarms shortly after startup. After ruling out a low coolant level, what is the next most likely cause to investigate?

Accepted Answer

Clogged radiator fins or restricted airflow

Answer

Faulty coolant temperature sensor

Answer

Incorrect fuel-to-air ratio

Answer

Low oil pressure

Question 2

When performing a load bank test on a standby generator, what parameter is used to verify the unit can sustain rated output?

Accepted Answer

Voltage regulation under full rated kW load

Answer

No-load frequency stability

Answer

Idle speed RPM

Answer

Battery charge current

Question 3

A diesel engine cranks but will not start. Fuel pressure is confirmed adequate. Which component failure could prevent fuel injection from occurring?

Accepted Answer

Defective fuel injection solenoid or ECM

Answer

Faulty radiator cap

Answer

Worn alternator brushes

Answer

Low coolant temperature

Question 4

What is the purpose of an automatic voltage regulator (AVR) self-test function found on modern generator control panels?

Accepted Answer

To verify the AVR can maintain voltage within specified limits under simulated conditions

Answer

To calibrate the fuel governor

Answer

To test the battery charger output

Answer

To reset the maintenance timer

Question 5

A generator producing voltage but tripping on overcurrent when connected to a known good load most likely has which problem?

Accepted Answer

Undersized circuit breaker or a misconfigured overcurrent relay setpoint

Answer

Defective coolant thermostat

Answer

Low engine oil level

Answer

Incorrect air filter restriction

Question 6

During preventive maintenance, technicians measure insulation resistance on generator windings. What minimum IR value in megohms is typically considered acceptable for a low-voltage generator?

Accepted Answer

1 MΩ

Answer

0.1 MΩ

Answer

10 MΩ

Answer

100 MΩ

Question 7

What condition does wet stacking in a diesel generator indicate, and how is it typically corrected?

Accepted Answer

Unburned fuel accumulation in the exhaust due to chronic light loading; corrected by running the engine at 75–100% load

Answer

Overloading; reduce load below rated kW

Answer

Coolant contamination of oil; corrected by flushing the cooling system

Answer

High ambient temperature operation; corrected by adding supplemental cooling