Breaker Insertion Handle Misalignment & Close Failure

Breaker Insertion Handle Misalignment & Close Failure

This article addresses a specific issue reported with breaker insertion handle misalignment and the inability to perform a CLOSE operation.

The root cause has been identified, and corrective actions are outlined below for reference and troubleshooting.

 Issue Summary

  • Symptoms:

    • Handle insertion misalignment with racking interface

    • Breaker unable to CLOSE in either TEST or CONNECT position

Root Cause

As observed in the field and shown in the reference image, the Sliding Plate on the right-side girder was not properly inserted into the rectangular rail slot.

  • During racking operation (clockwise handle rotation), the breaker was moved without ensuring the Sliding Plate was aligned, preventing the breaker from reaching the correct TEST or CONNECT position.

  • Required insertion depth:

    • TEST Position: 50 mm

    • CONNECT Position: 490 mm

  • In this misaligned state, mechanical and electrical interlocks are not released, resulting in CLOSE failure.

Corrective Actions

  1. Adjust the right-side girder to match the position of the left-side girder.

    • If deformation is found in the truck girder, replacement of the truck is recommended.

  2. Ensure the Sliding Plate (yellow circle in image) is properly inserted into the rectangular slot on the rail (red box).

  3. Retry breaker insertion and verify that CLOSE operation works normally.

 Additional Notes

  • Misalignment may have caused mechanical deformation due to repeated incorrect insertion attempts.

  • Always check Sliding Plate and girder positions before racking operation.