Which action should be taken when Phase Break is active and the PB indicator is lit?

Which action should be taken when Phase Break is active and the PB indicator is lit?

• A. Ignore the PB and continue at normal speed.
• B. Reduce speed and proceed without changes.
• C. Place throttle OFF and open the MCB until the PB is passed.
• D. Stop completely and wait for a signal.

Answer: (C)

When a Phase Break is detected and the PB indicator is lit, the system is telling you there’s a fault in the traction power circuit that could damage equipment or create unsafe conditions if you continue normally. The safest and most effective action is to cut propulsion and isolate the traction system until the fault is resolved. Placing the throttle to OFF stops any attempt to accelerate, and opening the Master Circuit Breaker removes power from the traction motors, preventing further electrical stress on the damaged phase. This protects the equipment and keeps crew and passengers safe while you wait for the PB indication to clear or for a signal indicating it’s safe to proceed. Ignoring the PB, or maintaining or only reducing speed without removing power, risks damage or unsafe motion. Stopping completely and waiting for a signal may be prudent in some situations, but the immediate protective action is to de-energize the traction circuit as described.

When a Phase Break is detected and the PB indicator is lit, the system is telling you there’s a fault in the traction power circuit that could damage equipment or create unsafe conditions if you continue normally. The safest and most effective action is to cut propulsion and isolate the traction system until the fault is resolved. Placing the throttle to OFF stops any attempt to accelerate, and opening the Master Circuit Breaker removes power from the traction motors, preventing further electrical stress on the damaged phase. This protects the equipment and keeps crew and passengers safe while you wait for the PB indication to clear or for a signal indicating it’s safe to proceed. Ignoring the PB, or maintaining or only reducing speed without removing power, risks damage or unsafe motion. Stopping completely and waiting for a signal may be prudent in some situations, but the immediate protective action is to de-energize the traction circuit as described.