MDE Unit 7 overspeed trip testing proceedures Flashcards

MDE Unit 7 overspeed trip testing proceedures

Question 5: Which safety cut-out is specifically designed to detect and prevent excessive exhaust gas temperatures?

A) Exhaust temperature trip

Overspeed Trip of the Centrifugal Type

Question 1: What is the primary purpose of an overspeed trip of the centrifugal type in a diesel engine?

C) To prevent engine damage by stopping the engine if it exceeds a predetermined speed

Question 3: What does a high coolant temperature trip do in a diesel engine?

B) It shuts down the engine if the coolant temperature exceeds a set threshold

Low Fuel Level Cut-Out

Question 4: How does a low fuel level cut-out function in a diesel engine?

B) Stops the engine when the fuel level drops below a certain threshold

Question 2: Which safety cut-out is designed to prevent engine operation in the event of low oil pressure?

A) Oil pressure cut-out

Oil Pressure Cut-Out

Question 2: How does an oil pressure cut-out function in a diesel engine?

C) Monitors oil pressure and stops the engine when pressure is too low

6. Vibration Sensor

Question: What is the purpose of a vibration sensor on a propulsion engine?

B) To monitor and detect abnormal vibrations that could indicate mechanical failure

High Coolant Temperature Trip

Question 3: How does a high coolant temperature trip function in a diesel engine?

C) Senses coolant temperature and halts engine operation when overheating occurs

5. Oil Mist Detector

Question: What is the reason for fitting an oil mist detector in a propulsion engine’s crankcase?

B) To detect the presence of oil mist that could indicate a crankcase explosion risk

Manual Testing of HT Cooling Water High-Temperature Alarm

Question 1: What is the first step in manually testing the set point for the high-temperature alarm on a diesel generator’s HT cooling water system?

C) Gradually heat the HT cooling water while monitoring the temperature

9. Propeller Shaft Bearing Temperature Sensor

Question: Why is a temperature sensor fitted to the propeller shaft bearing?

B) To detect overheating in the bearing that could lead to failure

10. Lube Oil Filter Differential Pressure Gauge

Question: What is the purpose of a differential pressure gauge on the lube oil filter in a propulsion engine?

B) To monitor the pressure difference across the filter and indicate when it needs cleaning or replacement

Question 4: What is the purpose of a low fuel level cut-out in a diesel engine?

C) To stop the engine if the fuel level falls below a certain point

8. Gearbox Temperature Sensor

Question: What is the role of a gearbox temperature sensor in a propulsion engine arrangement?

B) To detect excessive heat that could damage the gearbox components

Manual Testing of Lubricating Oil Low-Pressure Alarm

Question 1: What is the first step in manually testing the set point for the low-pressure alarm on a diesel engine’s lubricating oil system using a pressure calibrator?

C) Gradually decrease the applied pressure using the pressure calibrator while monitoring the alarm system

Question 5: Which of the following is a common maintenance check for the centrifugal overspeed trip mechanism?

B) Inspecting the condition of the centrifugal weights and springs

Question 3: What component of the centrifugal overspeed trip mechanism is responsible for detecting excessive engine speed?

B) The centrifugal governor

Question 4: What happens to the centrifugal overspeed trip mechanism if the engine speed returns to normal after an overspeed condition?

B) The trip mechanism automatically resets once the speed decreases

Safety Cut-Outs/Trips for Diesel Engines

Question 1: What is the primary function of an overspeed trip in a diesel engine?

B) To stop the engine if it exceeds a specified speed

Restoring Normal Operation After Testing

Question 4: After manually testing the lubricating oil low-pressure alarm and shutdown using a pressure calibrator, what should be the next step?

B) Reconnect the pressure sensor and reset the alarm and shutdown systems to their normal settings

Verifying Set Points on HT Cooling Water Alarm and Shutdown

Question 3: After manually testing the high-temperature alarm and shutdown set points, what should be done to verify the accuracy of these set points?

B) Record the temperatures at which the alarm and shutdown occurred and compare them with the set points

Manual Testing of Lubricating Oil Low-Pressure Shutdown

Question 2: During the manual testing of the lubricating oil low-pressure shutdown set point, what should you do if the shutdown does not activate at the expected pressure?

C) Verify the calibration of the pressure calibrator and retest

3. Overload Clutch

Question: What is the purpose of an overload clutch in a gearbox arrangement?

B) To protect the gearbox from damage due to excessive torque

2. High-Temperature Alarm

Question: Why is a high-temperature alarm fitted to the cooling system of a propulsion engine?

B) To alert the crew of excessive engine temperature that could cause overheating and damage

Verifying Set Points on Lubricating Oil Low-Pressure Alarm and Shutdown

Question 3: How should the set points be verified after manually testing the lubricating oil low-pressure alarm and shutdown?

B) Compare the alarm and shutdown activation pressures with the specified set points

1. Low Oil Pressure Alarm

Question: What is the primary reason for fitting a low oil pressure alarm to a propulsion engine?

C) To warn of inadequate lubrication that could lead to engine damage

Final System Check After Testing

Question 5: What is the purpose of performing a final system check after testing the lubricating oil low-pressure alarm and shutdown?

C) To confirm that the pressure alarm and shutdown system are functioning correctly after being reset

Restoring Normal Operation After Testing

Question 4: What is the final step after manually testing the HT cooling water high-temperature alarm and shutdown on a diesel generator?

C) Reset the alarm and shutdown systems and return the HT cooling system to normal operation

Manual Testing of HT Cooling Water High-Temperature Shutdown

Question 2: How is the high-temperature shutdown set point manually tested on a diesel generator?

B) By gradually heating the HT cooling water until the shutdown occurs

Overspeed Trip

Question 1: How does an overspeed trip function in a diesel engine?

B) Uses centrifugal force to activate the cut-out when speed exceeds the limit

4. Shaft Brake

Question: Why might a shaft brake be fitted to a propulsion engine?

B) To prevent the propeller from rotating when the engine is stopped

Question 2: How does a centrifugal overspeed trip mechanism operate?

C) It relies on centrifugal force to actuate a trip mechanism that stops the engine when a certain speed is exceeded

7. Emergency Stop Button

Question: Why is an emergency stop button fitted to a propulsion engine control system?

B) To quickly shut down the engine in case of an emergency

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