System Troubleshooting and Maintenance Flashcards
7 cards from real EGSA practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 System Troubleshooting and Maintenance flashcards as text
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?
Answer: Clogged radiator fins or restricted airflow
Clogged radiator fins or restricted airflow are common causes of overheating once low coolant level has been ruled out.
When performing a load bank test on a standby generator, what parameter is used to verify the unit can sustain rated output?
Answer: Voltage regulation under full rated kW load
Voltage regulation under full rated kW load confirms the generator can sustain its nameplate output without excessive voltage drop.
A diesel engine cranks but will not start. Fuel pressure is confirmed adequate. Which component failure could prevent fuel injection from occurring?
Answer: Defective fuel injection solenoid or ECM
A defective fuel injection solenoid or ECM can prevent fuel from being injected even when supply pressure is adequate.
What is the purpose of an automatic voltage regulator (AVR) self-test function found on modern generator control panels?
Answer: To verify the AVR can maintain voltage within specified limits under simulated conditions
The AVR self-test verifies that voltage regulation circuits function correctly within specified limits before a live load event.
A generator producing voltage but tripping on overcurrent when connected to a known good load most likely has which problem?
Answer: Undersized circuit breaker or a misconfigured overcurrent relay setpoint
An undersized breaker or misconfigured overcurrent relay will trip prematurely when the load is within the generator's rated capacity.
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?
Answer: 1 MΩ
A minimum of 1 MΩ is the general industry-accepted threshold for low-voltage generator winding insulation resistance.
What condition does wet stacking in a diesel generator indicate, and how is it typically corrected?
Answer: Unburned fuel accumulation in the exhaust due to chronic light loading; corrected by running the engine at 75–100% load
Wet stacking results from unburned fuel accumulating in the exhaust when a diesel runs at insufficient load, and is resolved by load banking to 75–100% capacity.