HV - High Voltage Safety Officer & Switchgear Operations Exit Exam Questions - Set 1

Question 1

What voltage level is defined as High Voltage (HV) under marine SOLAS and STCW regulations?

Accepted Answer

A: AC voltage exceeding 1,000 Volts (1 kV) between conductors, or >600V to earth

Answer

B: > 24V

Answer

C: > 100,000V

Answer

D: > 110V

Question 2

What is the primary hazard of working on High Voltage marine equipment compared to Low Voltage?

Accepted Answer

C: Severe electric arc flash explosion, high-energy blast, and arcing across air gaps

Answer

A: Magnetic tool attraction

Answer

B: Low sound

Answer

D: Slightly warm wires

Question 3

What safety document MUST be issued before performing maintenance on High Voltage switchgear?

Accepted Answer

C: High Voltage Permit to Work (PTW) and Sanction to Test

Answer

A: Verbal approval

Answer

B: Deck log entry

Answer

D: Hot Work Permit only

Question 4

What mandatory step must be taken immediately after opening an HV circuit breaker and isolator?

Accepted Answer

C: Prove equipment dead using approved calibrated HV voltage detector, then apply safety earths

Answer

A: Touch with bare hand

Answer

B: Spray water

Answer

D: Turn on generator

Question 5

What medium is commonly used inside modern High Voltage marine circuit breakers for arc quenching?

Accepted Answer

C: Vacuum (VCB) or Sulfur Hexafluoride gas (SF6)

Answer

A: Water bath

Answer

B: Compressed oxygen

Answer

D: Mineral oil

Question 6

What safety equipment must be worn when racking in or out an HV circuit breaker truck?

Accepted Answer

D: Arc flash protection suit (rated cal/cm2), arc flash visor/hood, HV insulating gloves, and ear protection

Answer

A: Leather apron

Answer

B: T-shirt and glasses

Answer

C: Cotton coveralls

Question 7

What is the purpose of earthing switches or portable earthing leads on isolated HV equipment?

Accepted Answer

A: Discharge residual capacitive charge and short-circuit conductors to ground for safety

Answer

B: Charge batteries

Answer

C: Increase voltage

Answer

D: Improve power factor

Question 8

What key interlock system is used to enforce strict mechanical sequence during HV switching operations?

Accepted Answer

D: Castell Key Interlock System

Answer

A: Combination lock

Answer

B: Card swipe

Answer

C: Master padlock

Question 9

What instrument is used to measure insulation resistance of High Voltage cables and machinery?

Accepted Answer

B: High Voltage Megohmmeter (Megger - 2.5 kV or 5 kV DC test voltage)

Answer

A: Hydrometer

Answer

C: Oscilloscope

Answer

D: Low voltage multimeter

Question 10

Who is authorized to issue a High Voltage Permit to Work on a ship?

Accepted Answer

B: Certified High Voltage Authorised Person (HVAP) / Chief Engineer / Senior Electrical Officer

Answer

A: Any deck rating

Answer

C: Chief Steward

Answer

D: Port Watchman

Question 11

Under STCW Code Table A-III/1-HV, what is the mandatory requirement regarding regulatory compliance and STCW code requirements during High Voltage Safety & Switchgear operations?

Accepted Answer

A: Strict compliance with approved safety procedures and flag state regulations

Answer

B: Verbal recommendation without documentation

Answer

C: Optional adherence based on vessel size

Answer

D: Applicable only during drydock operations

Question 12

What specific safety precaution must be observed when managing regulatory compliance and STCW code requirements for High Voltage Safety & Switchgear on board?

Accepted Answer

B: Conducting a thorough risk assessment and briefing all involved personnel prior to starting work

Answer

A: Disabling automated safety alarms to save time

Answer

C: Delegating tasks exclusively to untrained crew members

Answer

D: Proceeding without informing the officer on watch

Question 13

What is creepage distance on High Voltage insulators?

Accepted Answer

D: Shortest distance along outer surface of insulating material between two conductive parts

Answer

A: Distance between bow and stern

Answer

B: Cable length

Answer

C: Busbar thickness

Question 14

What condition occurs when electrical stress breaks down insulating properties of air or solid insulation?

Accepted Answer

C: Dielectric breakdown / Flashover

Answer

A: Magnetic hysteresis

Answer

B: Phase sync

Answer

D: Resistance increase

Question 15

What is the function of a Potential Transformer (PT) / Voltage Transformer (VT) in HV switchboards?

Accepted Answer

C: Step down High Voltage (e.g. 6.6 kV) to safe Low Voltage (e.g. 110V) for metering and relays

Answer

A: Step up to 100 kV

Answer

B: Cool generators

Answer

D: Convert AC to DC

Question 16

What is the function of a Current Transformer (CT) in HV switchgear?

Accepted Answer

D: Step down high primary currents (e.g. 1000A) to standard low secondary currents (1A or 5A) for relays

Answer

A: Store energy

Answer

B: Step up to 10,000A

Answer

C: Measure water temp

Question 17

What protective relay detects imbalances between incoming and outgoing currents in HV generator windings?

Accepted Answer

A: Differential Protection Relay (87G)

Answer

B: Under Voltage Relay (27)

Answer

C: Reverse Power Relay (32)

Answer

D: Over Frequency Relay (81)

Question 18

What is the function of a Neutral Grounding Resistor (NGR) in marine HV electrical systems?

Accepted Answer

B: Limit earth fault current to a safe value (e.g. 10A - 20A), preventing core damage during single phase-to-ground faults

Answer

A: Ground antenna

Answer

C: Increase fault current

Answer

D: Heat engine room

Question 19

What hazard is associated with opening the secondary circuit of an energized Current Transformer (CT)?

Accepted Answer

B: Extremely high induced open-circuit voltage causing lethal electric shock and explosive CT failure

Answer

A: Fuse blows

Answer

C: CT cools down

Answer

D: Voltage drops to zero

Question 20

What testing device is used to check insulation integrity of HV rubber gloves before use?

Accepted Answer

A: Manual air inflation pump / glove tester to check for pinhole leaks, plus visual inspection

Answer

B: Seawater dip

Answer

C: Pliers stretch

Answer

D: Flame check

Question 21

What color is standard for High Voltage warning hazard signs on marine switchboards?

Accepted Answer

B: Yellow background with black skull/lightning symbol and 'DANGER - HIGH VOLTAGE' text

Answer

A: Green sign

Answer

C: Pink sign

Answer

D: White sign with blue text

Question 22

What protection is provided by a Reverse Power Relay (32) on a marine HV generator?

Accepted Answer

C: Trips generator breaker if electrical power flows BACK into generator (motoring the prime mover)

Answer

A: Protects high temp

Answer

B: Protects low oil

Answer

D: Protects low frequency

Question 23

Which international regulation specifies the minimum standard for regulatory compliance and STCW code requirements concerning High Voltage Safety & Switchgear?

Accepted Answer

D: STCW Code Section A-III/1-HV and relevant SOLAS/MARPOL conventions

Answer

A: Port State Control advisory note only

Answer

B: Tonnage Measurement Convention 1969

Answer

C: International Load Line Certificate Annex 3

Question 24

In the event of an emergency involving regulatory compliance and STCW code requirements during High Voltage Safety & Switchgear tasks, what immediate action is required?

Accepted Answer

C: Raise the alarm, notify the Officer of the Watch, and execute assigned muster list duties

Answer

A: Attempt to resolve the incident silently without raising the alarm

Answer

B: Evacuate the vessel immediately without informing the bridge

Answer

D: Wait until the end of the watch to log the issue

Question 25

What is the purpose of an Arc Flash Detection system inside HV switchboard cubicles?

Accepted Answer

D: Detect light flash via fiber-optic sensors and trip main breaker in milliseconds before pressure explosion develops

Answer

A: Turn on cabin lights

Answer

B: Detect smoke

Answer

C: Take photos

Question 26

What is partial discharge (PD) in High Voltage electrical apparatus?

Accepted Answer

C: Microscopic electrical sparks inside insulation voids that gradually erode dielectric strength

Answer

A: Battery charge

Answer

B: Load shedding

Answer

D: Complete breaker trip

Question 27

What insulation class is standard for marine HV electric motor windings (Class F or Class H)?

Accepted Answer

D: Class F (155°C max temp) or Class H (180°C max temp) with vacuum pressure impregnation (VPI)

Answer

A: Wood insulation

Answer

B: Paper insulation

Answer

C: Cotton thread

Question 28

What device is used to safely discharge stored electrical energy in large HV capacitor banks before maintenance?

Accepted Answer

D: Built-in discharge resistors and portable earthing/shorting probe

Answer

A: Water spray

Answer

B: Screwdriver touch

Answer

C: Fan

Question 29

What safety distance (air clearance) must be maintained from exposed un-insulated 6.6 kV conductors?

Accepted Answer

B: Minimum safe clearance distance (~150 mm to 250 mm depending on standard, plus safety margin)

Answer

A: 1 mm

Answer

C: Zero

Answer

D: 10 meters

Question 30

What test is performed to measure moisture and gas breakdown in SF6 circuit breaker gas?

Accepted Answer

B: SF6 gas purity, dew point, and decomposition product analysis

Answer

A: Titration

Answer

C: Salt water test

Answer

D: Smoke test

High Voltage Safety Officer & Switchgear Operations (HV) (Set 1)

What voltage level is defined as High Voltage (HV) under marine SOLAS and STCW regulations?

Questions in HV Set 1

Question Discussion & Notes

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