Operational Instructions of A-9 Handle in 3 Phase Locomotives during BP overcharge cycle

Technical

Circular Number: DCKP/CIR/TechEL/23-10-2024/10.244.207.211/1

🚂 Instructions for Loco Pilots (LP) & Assistant Loco Pilots (ALP)
1
If the A-9 handle is moved to the APPLICATION position during the LPO (BP overcharge cycle), the brakes will apply.
Once the A-9 handle is moved back to the RUN position, the brakes will release, but the BP will re-initiate another overcharge cycle.
2
⚠️ Important: If, during this process, the A-9 handle is mistakenly set to the MIN position, the BP gauge may display a pressure of around 5.0 kg/cm², but the brakes will remain applied.
The BC gauge will show applied pressure.
3
✅ Before proceeding: LPs must ensure that:
  • A-9 handle is in the RUN position.
  • BP pressure is 5.0 kg/cm².
Only after confirming both conditions should operations proceed.
🔧 CCB Locomotives
4
In CCB locos, if the CE (Control Electronics) is turned OFF and then ON during an overcharge cycle, the BC gauge will display approximately 1 kg/cm² after the loco is re-energized and BP is charged to 5.0 kg/cm².
5
Corrective Procedure

In this situation, the LP should:

  1. Move the A-9 handle to the RELEASE position.
    → This releases the BC pressure.
  2. Then shift the A-9 handle to the RUN position.
⚠️ Final Reminder
Always verify the A-9 handle position and BP/BC gauge indications before proceeding with locomotive operations.

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