What risk occurs if a generator breaker is closed out of phase (e.g. 180° out of phase) with live HV busbar?
Direct Answer
Option B: Severe mechanical torque shock shearing generator shaft, massive fault current, and switchboard explosion
Closing a breaker 180° out of phase creates a massive potential difference, causing instantaneous fault currents that exceed the mechanical design limits of the generator shaft and switchgear. This catastrophic event leads to severe torque shock, potential shaft shearing, and explosive arc flash incidents, violating fundamental synchronization safety protocols defined in IEC 60092-503.
All Options
Detailed Explanation & Context
Closing a breaker 180° out of phase creates a massive potential difference, causing instantaneous fault currents that exceed the mechanical design limits of the generator shaft and switchgear. This catastrophic event leads to severe torque shock, potential shaft shearing, and explosive arc flash incidents, violating fundamental synchronization safety protocols defined in IEC 60092-503.
Relevant Framework: STCW 2010 Manila Amendments • DG Shipping E-Learning & Exit Exam Standards • High Voltage Safety Officer & Switchgear Operations (HV).
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