MDE Unit 14 start systems Flashcards

MDE Unit 14 start systems

Question 4:
The low lube oil pressure interlock in a direct air start medium-speed diesel engine is designed to:

B) Prevent starting if lube oil pressure is below a safe threshold

Question 3:

How is the solenoid activated in a solenoid-operated starting system?

D) By a current flowing through its coil

Question 2:

Which component of the electric starting system provides the electrical power needed to turn the starter motor?

C) Battery

Question 2:
During which stroke of a four-stroke diesel engine cycle is the air start valve usually open?

B) Compression stroke

Question 6:

Which component prevents the starter motor from operating when the engine is already running?

D) Starter inhibitor switch

Question 3: During an attempt to start a large marine diesel engine, you find that no air is being delivered to the cylinders. What could be a likely cause?

C. Closed starting air supply valve.

Question 1:
Which of the following interlocks is most commonly fitted to a direct air start medium-speed diesel engine to prevent the engine from starting if the turning gear is engaged?

B) Turning gear engagement interlock

Question 2:
What is the function of the starting air interlock in a direct air start medium-speed diesel engine?

C) To prevent starting if the main starting air valve is not fully open

Question 6:

In a hydraulic oil start system, what is the purpose of the hydraulic control valve?

A) To regulate the flow of hydraulic fluid to the starting motor

Question 3:

Which interlock is commonly found in a diesel engine hydraulic oil start system to ensure safe operation?

B) Hydraulic fluid level sensor

Question 4:

What role does the hydraulic accumulator play in the hydraulic oil start system of a diesel engine?

C) It maintains hydraulic pressure for starting the engine

Question 3:
How does the timing of the air start valve's opening relate to the inlet and exhaust valves' operation in a four-stroke diesel engine?

A) The air start valve opens when both inlet and exhaust valves are closed

Question 1:

What is the primary function of the solenoid in a solenoid-operated, battery-powered electric starting system?

B) To engage the starter motor with the engine’s flywheel

Question 3:
Which interlock prevents a medium-speed diesel engine from being started if the engine's crankcase doors are open?

B) Crankcase door interlock

Question 1:
What is the primary purpose of regularly checking the air pressure in the air motor starting system?

A) To ensure the air motor operates at the correct speed

Question 4:

Which of the following describes the role of the starter motor in the electric starting system?

C) To crank the engine and initiate combustion

Question 1:
Which of the following is a safety device commonly fitted to the air starting system of a large medium-speed marine diesel engine?

 

A) Pressure relief valve

Question 5:
During a routine check, what should be done if moisture is found in the air motor's air supply line?

B) Drain the moisture and inspect the air dryer or moisture separator

Question 4: What should be inspected if there is air leakage during the start sequence of a marine diesel engine?

B. Starting air valve condition.

Question 7:

What is the purpose of the starter relay in an electric starting system?

C) To amplify the current to the starter motor

Question 1:

What is the primary function of the hydraulic oil start system in a diesel engine?

C) To initiate the engine’s start-up by engaging the starting mechanism

Question 2:
What is the primary function of the non-return valve in the air starting system of a medium-speed marine diesel engine?

A) To prevent backflow of air into the receiver

Question 1:
At what approximate crank angle does the air start valve typically begin to open on a four-stroke diesel engine during the starting process?

A) 0° (TDC)

Question 3:
In an air starting system, the interlock system is designed to:

A) Ensure that the engine cannot be started unless the turning gear is disengaged

Question 2:

Which of the following components is typically included in a diesel engine hydraulic oil start system?

A) Hydraulic pump

Question 5:

What happens when the starter switch is turned on in a solenoid-operated starting system?

B) The solenoid engages the starter motor and the engine cranks

Question 5:

Which safety interlock prevents the hydraulic oil start system from operating if certain conditions are not met?

A) Hydraulic pressure switch

Question 3:
Why is it important to inspect the condition of the air motor’s drive gear during routine maintenance?

B) To ensure the gear is properly aligned with the engine's flywheel

Question 2: If an engine does not start when initiating the start sequence, and the air start lever is in the correct position, what should be the next step?

A. Check for leaks in the starting air system.

Question 5: Which of the following could cause a failure to start in a large marine diesel engine due to an issue with the air starting system?

A. Air start valve stuck in the open position.

Question 4:
What is a common sign that the air motor’s exhaust port needs to be inspected or cleaned?

A) Reduced engine starting speed

Question 4:
Which safety device in the air starting system is responsible for releasing excess air to the atmosphere in case of an overpressure condition?

A) Safety valve

Question 4:
What is the significance of the crank angle at which the air start valve closes on a four-stroke diesel engine?

B) It prevents the backflow of exhaust gases into the starting air system

Question 1: When initiating the start sequence on a large medium-speed marine diesel engine with individual air starting valves, the engine fails to start. Which of the following is the first check you should perform?

B. Check if the main starting air receiver is pressurized.

Question 2:
Which of the following is a key maintenance task for the air motor to prevent corrosion and ensure long-term reliability?

A) Lubricating the air motor components regularly
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