LEC Electrical & Electronic Systems 2

Question 1

What is the primary function of the main reservoir in a locomotive's pneumatic/electrical control system?

Accepted Answer

Store compressed air for brakes and controls

Answer

The main reservoir stores compressed air used to operate brakes, whistles, and various pneumatic controls on the locomotive.

Question 2

Which component converts AC power from the alternator into DC power for traction motors on a diesel-electric locomotive?

Accepted Answer

Rectifier

Answer

A rectifier converts alternating current (AC) produced by the main alternator into direct current (DC) used by the traction motors.

Question 3

A locomotive's cab signals display a 'Restricting' aspect. What does this indicate to the engineer?

Accepted Answer

Proceed prepared to stop short of a train, obstruction, or switch

Answer

A Restricting cab signal indicates the engineer must proceed prepared to stop short of any obstruction, typically requiring reduced speed.

Question 4

What is the purpose of a ground relay on a locomotive?

Accepted Answer

Detect and isolate electrical faults to ground in traction circuits

Answer

A ground relay detects unintended electrical paths to ground in the high-voltage traction circuit and isolates the affected circuit to prevent damage.

Question 5

When a locomotive experiences a 'wheel slip' indication, which system is primarily responding?

Accepted Answer

Wheel slip detection and correction system

Answer

The wheel slip detection and correction system monitors axle speed differentials and reduces tractive effort to restore adhesion when slipping is detected.

(LEC) Locomotive Engineer Certification Practice Test

(LEC) Locomotive Engineer Certification Practice Test

LEC Electrical & Electronic Systems 2