Electrical & Electronic Systems Flashcards
7 cards from real LEC practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Electrical & Electronic Systems flashcards as text
What is the voltage range typically used for battery systems on a modern diesel-electric freight locomotive?
Answer: 64–74 volts DC
Most diesel-electric freight locomotives use a 64–74 volt DC battery system to power starting circuits, control systems, and lighting when the engine is off.
An engineer notices the 'low oil pressure' light illuminating while running at full throttle. What is the correct initial response?
Answer: Reduce throttle and notify dispatch while monitoring the situation
Reducing throttle decreases engine load while monitoring oil pressure; the engineer should notify dispatch and follow railroad procedures to protect the prime mover.
What is the function of the load regulator on a diesel-electric locomotive?
Answer: Controls fuel delivery to maintain constant engine RPM under varying loads
The load regulator adjusts the electrical load on the main alternator to maintain constant engine RPM regardless of traction power demands.
Which system on a locomotive continuously monitors axle bearing temperatures and alerts the crew to overheating?
Answer: Onboard bearing temperature monitoring system
The onboard bearing temperature monitoring system uses sensors on each axle to detect abnormal heat and alert the engineer before a hotbox failure occurs.
A locomotive's electrical system shows repeated tripping of the same circuit breaker. What should the engineer do?
Answer: Reset once; if it trips again, leave it open and report it
Resetting a circuit breaker once is permitted; if it trips again, leaving it open prevents fire or further damage, and the fault must be reported.
What does 'MU (multiple unit) operation' require regarding electrical connections between locomotives?
Answer: A 27-point electrical MU cable connecting control circuits between units
MU operation uses a 27-point electrical cable (jumper) to connect the control circuits of multiple locomotives so one engineer can control all units simultaneously.
What is the purpose of the event recorder (black box) on a locomotive?
Answer: Capture operational data such as speed, brake applications, and throttle position
The locomotive event recorder captures data including speed, throttle position, brake pipe pressure, and other operational parameters for accident investigation and compliance.