Under double Pantograph operation, how should the pantographs be configured for the leading and trailing units when approaching a Phase Break (PB), if PB is lit?

Under double Pantograph operation, how should the pantographs be configured for the leading and trailing units when approaching a Phase Break (PB), if PB is lit?

• A. Leading unit: Pantographs Up; Trailing unit: Front Pantograph Up.
• B. Leading unit: Pantographs Down; Trailing unit: All Pantographs Down.
• C. Leading unit: All Pantographs Up; Trailing unit: All Pantographs Up.
• D. Leading unit: both Pantographs Up; Trailing unit: rear Pantograph Up.

Answer: (D)

Maintaining power continuity across a Phase Break with a double pantograph setup relies on selecting the right pantograph configuration for the lead and trailing units. When the PB light is on, the leading unit should have both pantographs up to maximize contact and bridge the transition across the break, ensuring stable current pickup as the front of the train passes into the next catenary section. The trailing unit should keep only the rear pantograph up, providing a reliable pickup for the rest of the train while avoiding additional pantographs contacting the wires at the break, which helps reduce arcing and potential contact issues. This arrangement preserves power flow through the PB and minimizes electrical risk as the train continues.

Maintaining power continuity across a Phase Break with a double pantograph setup relies on selecting the right pantograph configuration for the lead and trailing units. When the PB light is on, the leading unit should have both pantographs up to maximize contact and bridge the transition across the break, ensuring stable current pickup as the front of the train passes into the next catenary section. The trailing unit should keep only the rear pantograph up, providing a reliable pickup for the rest of the train while avoiding additional pantographs contacting the wires at the break, which helps reduce arcing and potential contact issues. This arrangement preserves power flow through the PB and minimizes electrical risk as the train continues.