What should a tram driver do to safely perform the electrical connection of the carriages?
Show the correct answer
Correct answer
C. Lower the pantograph and disconnect the batteries.
Explanation
This question is about connecting tram cars electrically. To connect tram cars electrically in a safe way, the tram driver should lower the pantographs and disconnect the batteries - the answer is C.
The cables connecting the tram cars carry circuits supplied both from the overhead contact line and from the batteries. Lowering the pantographs cuts off the high voltage from the overhead line, and disconnecting the batteries cuts off the voltage of the auxiliary circuits. Only after both steps does joining the connectors carry no risk of electric shock or of a short circuit that could damage the electrical system. Lowering the pantographs alone (answer A) or disconnecting the batteries alone (answer B) does not remove all sources of voltage. These steps are carried out following the instructions.
Legal basis: Art. 66 para. 1 point 1 of the Road Traffic Act (Prawo o ruchu drogowym)