HV Exit Exam • Set 6 Question 5 of 30

The primary function of a protective relay in a power circuit breaker protection scheme is to:

✓

Direct Answer

Option B: Detect electrical faults and close trip contacts when measured parameters exceed predetermined thresholds

The protective relay constantly monitors system parameters (current, voltage, frequency, phase angle) and energizes the circuit breaker trip coil when an abnormal fault condition is detected.

All Options

Dissipate arcing current thermally

Detect electrical faults and close trip contacts when measured parameters exceed predetermined thresholds (Correct Answer)

Regulate the generator field excitation

Extinguish the arc inside the interrupter chamber

Detailed Explanation & Context

The protective relay constantly monitors system parameters (current, voltage, frequency, phase angle) and energizes the circuit breaker trip coil when an abnormal fault condition is detected.

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

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