Which of the following reasons may cause an interruption in the flow of high voltage current directly to the wagon?
Show the correct answer
Correct answer
C. The graphite insert of the pantograph is chipped.
Explanation
This question is about interruptions in the supply of high-voltage current to the tram car. Such interruptions may be caused by a chipped graphite insert of the pantograph - the answer is C.
The graphite insert of the pantograph slides along the contact wire of the overhead contact line, and current flows through it to the tram. When it is chipped, it loses constant contact with the wire - the pantograph bounces, there is sparking and there are short breaks in the power supply. Damage to the battery (answer A) concerns the low-voltage circuits, not the supply from the overhead line, and the external bell (answer B) has no effect on the current supply. The tram driver checks the condition of the inserts before setting off and reports any damage.
Legal basis: Art. 66 para. 1 point 1 of the Road Traffic Act (Prawo o ruchu drogowym)