HV Exit Exam • Set 4 Question 17 of 30

In AC circuit breakers, natural arc interruption occurs when the alternating current waveform reaches:

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Direct Answer

Option B: Natural current zero (zero current)

In AC systems, current naturally passes through zero twice per cycle. At natural current zero, energy input ceases, allowing the dielectric medium to rapidly deionize and prevent arc restrike.

All Options

Peak positive voltage

Natural current zero (zero current) (Correct Answer)

Peak negative current

Maximum rate of voltage rise (dv/dt)

Detailed Explanation & Context

In AC systems, current naturally passes through zero twice per cycle. At natural current zero, energy input ceases, allowing the dielectric medium to rapidly deionize and prevent arc restrike.

Relevant Framework: STCW 2010 Manila Amendments • DG Shipping E-Learning & Exit Exam Standards • High Voltage Safety Officer & Switchgear Operations (HV).

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