How should a tram driver pass through the section isolator placed on the overhead line?
Show the correct answer
Correct answer
B. Coasting or braking.
Explanation
This question is about passing under section insulators of the overhead contact line. The tram driver should pass under them while coasting or braking - the answer is B.
A section insulator divides the overhead line into sections that are supplied separately. If the tram passes under it with the drive switched on (answer A), an electric arc forms when the circuit is broken; it burns the pantograph strip and damages the insulator. That is why you switch off the drive before an insulator, and the tram passes through using momentum - the tram will not stop under the insulator if you reach it at a suitable speed. The reasoning of answer C is wrong - the insulator does not conduct current, so the tram does not return energy to the overhead line through it, and you do not have to brake every time, because coasting is enough.
Legal basis: Art. 3 para. 1 of the Road Traffic Act (Prawo o ruchu drogowym)