If the insulation resistance between a circuit breaker phase terminal and earthed frame is found below acceptable limits, the probable root cause could be:
Direct Answer
Option D: Any of the above
Insulation resistance degradation is frequently caused by environmental contaminants like salt, moisture, or conductive carbon deposits from previous arcing events. These factors create leakage paths across bushings or within interrupter chambers. Regular megger testing and cleaning, as required by maintenance schedules under IEC 60092-503, are essential to prevent flashovers and ensure safe high-voltage system operation.
All Options
Detailed Explanation & Context
Insulation resistance degradation is frequently caused by environmental contaminants like salt, moisture, or conductive carbon deposits from previous arcing events. These factors create leakage paths across bushings or within interrupter chambers. Regular megger testing and cleaning, as required by maintenance schedules under IEC 60092-503, are essential to prevent flashovers and ensure safe high-voltage system operation.
Relevant Framework: STCW 2010 Manila Amendments • DG Shipping E-Learning & Exit Exam Standards • High Voltage Safety Officer & Switchgear Operations (HV).
Practice Full HV Set 6
Test yourself with 30 interactive questions, live timer, and instant score.