HV Exit Exam • Set 6 Question 11 of 30

Which of the following is NOT a standard mechanical operating mechanism type for circuit breakers?

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Direct Answer

Option D: Vacuum operating actuator (vacuum is an interrupting medium, not an actuator mechanism)

Vacuum refers to the arc quenching/interrupting medium inside interrupter bottles. Operating mechanisms that supply mechanical force are spring, pneumatic, hydraulic, or motor actuators.

All Options

Spring-charged mechanism

Pneumatic / Electro-pneumatic mechanism

Hydraulic mechanism

Vacuum operating actuator (vacuum is an interrupting medium, not an actuator mechanism) (Correct Answer)

Detailed Explanation & Context

Vacuum refers to the arc quenching/interrupting medium inside interrupter bottles. Operating mechanisms that supply mechanical force are spring, pneumatic, hydraulic, or motor actuators.

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

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