What effect could be caused by an electrical arc formed when passing through the isolator with an enabled drive?
Show the correct answer
Correct answer
B. Damage to the pantograph (current collector).
Explanation
This question is about passing through a section insulator of the overhead contact line with the drive switched on. The electric arc formed at that moment may damage the pantograph, that is the current collector - the answer is B.
A section insulator divides the overhead line into sections that are supplied separately. When the tram is drawing current and the pantograph strip passes through the insulator, the circuit is suddenly broken and an electric arc forms between the strip and the wire. The arc burns the contact strip and may damage the insulator itself and the contact wire. The arc forms where the strip touches the contact wire, not in the battery circuit, so it does not cause a drop in the battery voltage (answer A). The lightning arrester (answer C) protects against overvoltage caused by lightning. That is why you pass under an insulator while coasting, without drawing current.
Legal basis: Art. 3 para. 1 of the Road Traffic Act (Prawo o ruchu drogowym)