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 primary function of the main reservoir in a locomotive's pneumatic/electrical control system?
Answer: Store compressed air for brakes and controls
The main reservoir stores compressed air used to operate brakes, whistles, and various pneumatic controls on the locomotive.
Which component converts AC power from the alternator into DC power for traction motors on a diesel-electric locomotive?
Answer: Rectifier
A rectifier converts alternating current (AC) produced by the main alternator into direct current (DC) used by the traction motors.
A locomotive's cab signals display a 'Restricting' aspect. What does this indicate to the engineer?
Answer: Proceed prepared to stop short of a train, obstruction, or switch
A Restricting cab signal indicates the engineer must proceed prepared to stop short of any obstruction, typically requiring reduced speed.
What is the purpose of a ground relay on a locomotive?
Answer: Detect and isolate electrical faults to ground in traction circuits
A ground relay detects unintended electrical paths to ground in the high-voltage traction circuit and isolates the affected circuit to prevent damage.
When a locomotive experiences a 'wheel slip' indication, which system is primarily responding?
Answer: Wheel slip detection and correction system
The wheel slip detection and correction system monitors axle speed differentials and reduces tractive effort to restore adhesion when slipping is detected.
What does the term 'notch' refer to in relation to locomotive throttle operation?
Answer: A discrete throttle position that controls engine power output
A notch is a discrete throttle position on the controller that corresponds to a specific power output level, typically ranging from idle to Notch 8.
Which type of braking uses the traction motors as generators to slow the train?
Answer: Dynamic braking
Dynamic braking reconnects the traction motors as generators, converting kinetic energy into electrical energy (dissipated as heat) to slow the locomotive.