EWRB THEORY FINAL EXAM 2026 ACTUAL QUESTIONS
AND SOLUTIONS RATED A+
✔✔Define the term DISCRIMINATION in relation to electrical protection in an electrical
installation. - ✔✔The protective device CLOSEST to the fault operates before any other
protective device can operate.
✔✔State TWO methods used to cool transformers. - ✔✔ANY TWO:
- Air cooled
- Oil cooled
- Pumped or natural convection
- Forced or natural ventilation
✔✔State the main advantage of a single-phase synchronous motor when compared to
a single-phase induction motor. - ✔✔The synchronous motor rotates at a
constant speed independent of the load.
✔✔Describe how the output voltage of a large power transformer is maintained as the
load changes. - ✔✔A tap-changer is used to maintain the voltage.
✔✔Explain the term BURDEN as it relates to current transformers. - ✔✔It is the total VA
load that can be imposed on a CT.
✔✔State TWO methods of PHASE-SPLITTING used to provide the starting torque in a
single-phase induction motor. - ✔✔ANY TWO:
- A capacitor in series with the auxiliary winding
- Different winding impedances
- A shaded pole
✔✔State TWO devices that can be used to protect semi-conductor components against
the effect of transient voltages. - ✔✔ANY TWO:
- Snubber circuit
- MOV (surge diverter)
- Free-wheeling diode
- RC circuit
- Optocoupler/Relay
- UPS
✔✔State TWO factors that determine the voltage drop in a 400V, final subcircuit TPS
cable. - ✔✔ANY TWO:
- Length of cable
- Cross-sectional area
- Load
- Types of conductor material
,✔✔Explain why it is necessary to have a protective earthing conductor in a final
subcircuit protected by a RCD. - ✔✔In order for the RCD to operate, an earth leakage
path must exist.
✔✔What is the maximum resistance for the main earthing conductor? - ✔✔0.5Ω
✔✔How is the direction of a three-phase delta connected AC induction motor changed?
- ✔✔Interchange any two motor supply connections.
✔✔Define the term luminous flux. - ✔✔The quantity of light emitted by a light source.
✔✔For it to operate correctly, how should a Zener Diode be connected? - ✔✔Reversed
biased.
✔✔What is a BJT? - ✔✔Bi-polar Junction Transistor
✔✔What is a transducer? - ✔✔A device that converts energy from one form to another.
✔✔Explain how a fluorescent light produces a stroboscopic effect. - ✔✔The fluorescent
tube gives 100 flashes of light per second from the 50 Hz AC supply.
✔✔Identify the correct circuit - ✔✔The first step before isolating a circuit.
✔✔Prove-Test-Prove - ✔✔Ensures test instrument works before and after checking.
✔✔Lockout/tagout device - ✔✔Must be applied after switching off to prevent re-
energization.
✔✔Re-test your tester after proving dead - ✔✔To confirm the tester didn't fail during
testing.
✔✔PTP steps in order - ✔✔Prove tester → Test circuit → Prove tester again.
✔✔Cable management - ✔✔Important to reduce trip hazards and cable damage.
✔✔Poor housekeeping examples - ✔✔Tangled extension leads; liquids near live
equipment.
✔✔Fire tetrahedron elements - ✔✔Heat, fuel, oxygen, chemical chain reaction.
✔✔Safest extinguisher on energized electrical fire - ✔✔COI extinguisher.
,✔✔Fuse protection - ✔✔Protects the cable from overcurrent.
✔✔RCD trip current - ✔✔Typically trips at 30 mA.
✔✔PPE for electrical work - ✔✔Insulated gloves, safety glasses.
✔✔CAT IV meters - ✔✔Designed for utility connections and service entrances.
✔✔Earth bond test - ✔✔Used to verify continuity of protective earth conductors.
✔✔MEN stands for - ✔✔Multiple Earthed Neutral.
✔✔Safety advantages of MEN - ✔✔Effective fault current path; prevents dangerous
voltages.
✔✔MEN link location - ✔✔Found at the main switchboard.
✔✔Phase separation in a 3ph system - ✔✔120°.
✔✔Star-delta start method - ✔✔Reduces inrush current.
✔✔3ph motors efficiency - ✔✔Provide smoother torque and lower losses.
✔✔Capacitor-start motors - ✔✔Used for higher starting torque appliances like
compressors.
✔✔Shaded-pole motor - ✔✔Common in small fans.
✔✔NZ wiring rules standard - ✔✔AS/NZS 3000.
✔✔Portable appliance testing standard - ✔✔AS/NZS 3760.
✔✔Worker competency regulation - ✔✔Regulated by Electrical Workers Registration
Board (EWRB).
✔✔WorkSafe NZ responsibility - ✔✔Responsible for enforcing workplace safety
regulations.
✔✔Series circuit current - ✔✔The same through all components.
✔✔Power factor correction - ✔✔Improves efficiency and reduces reactive power.
✔✔Max volt drop for final subcircuits in NZ - ✔✔5% of nominal voltage.
, ✔✔TPS cable usage - ✔✔Used for fixed domestic wiring.
✔✔Flexible cords as fixed wiring - ✔✔Not mechanically protected or rated for
permanent installation.
✔✔Class I appliance requirement - ✔✔Must have protective earth connection.
✔✔Insulation resistance minimum value - ✔✔1 MΩ.
✔✔PAT testing frequency - ✔✔Depends on environment and appliance type.
✔✔Neutral conductor function - ✔✔Carries return current back to source.
✔✔Transformer function - ✔✔Changes voltage level (and current) via electromagnetic
induction.
✔✔Correct order to fight an electrical fire - ✔✔Disconnect power → Use COI or dry
powder.
✔✔RCD trip time at 30 mA leakage - ✔✔Should be under 300 ms (typical standard).
✔✔Personal protective grounding importance - ✔✔Prevents accidental energization or
shock.
✔✔What is the main focus of the EST topics that comprise approximately 70% of the
exam? - ✔✔Safety, including isolation, Prove Test Prove (PTP), workplace general
principles, fire safety, and extinguishers.
✔✔What are the components of fire safety mentioned in the EST study guide? - ✔✔Fire
tetrahedron and extinguishers.
✔✔What does 'MEN' refer to in the context of EST topics? - ✔✔MEN refers to Multiple
Earth Neutral systems and supply systems.
✔✔What types of motors are covered in the EST topics that make up approximately
70% of the exam? - ✔✔Three-phase motors.
✔✔What is the focus of the EST topics that comprise approximately 30% of the exam? -
✔✔Circuit theory, calculations, volt drop methods, single-phase motors, legislation, and
cable and cord types and uses.
AND SOLUTIONS RATED A+
✔✔Define the term DISCRIMINATION in relation to electrical protection in an electrical
installation. - ✔✔The protective device CLOSEST to the fault operates before any other
protective device can operate.
✔✔State TWO methods used to cool transformers. - ✔✔ANY TWO:
- Air cooled
- Oil cooled
- Pumped or natural convection
- Forced or natural ventilation
✔✔State the main advantage of a single-phase synchronous motor when compared to
a single-phase induction motor. - ✔✔The synchronous motor rotates at a
constant speed independent of the load.
✔✔Describe how the output voltage of a large power transformer is maintained as the
load changes. - ✔✔A tap-changer is used to maintain the voltage.
✔✔Explain the term BURDEN as it relates to current transformers. - ✔✔It is the total VA
load that can be imposed on a CT.
✔✔State TWO methods of PHASE-SPLITTING used to provide the starting torque in a
single-phase induction motor. - ✔✔ANY TWO:
- A capacitor in series with the auxiliary winding
- Different winding impedances
- A shaded pole
✔✔State TWO devices that can be used to protect semi-conductor components against
the effect of transient voltages. - ✔✔ANY TWO:
- Snubber circuit
- MOV (surge diverter)
- Free-wheeling diode
- RC circuit
- Optocoupler/Relay
- UPS
✔✔State TWO factors that determine the voltage drop in a 400V, final subcircuit TPS
cable. - ✔✔ANY TWO:
- Length of cable
- Cross-sectional area
- Load
- Types of conductor material
,✔✔Explain why it is necessary to have a protective earthing conductor in a final
subcircuit protected by a RCD. - ✔✔In order for the RCD to operate, an earth leakage
path must exist.
✔✔What is the maximum resistance for the main earthing conductor? - ✔✔0.5Ω
✔✔How is the direction of a three-phase delta connected AC induction motor changed?
- ✔✔Interchange any two motor supply connections.
✔✔Define the term luminous flux. - ✔✔The quantity of light emitted by a light source.
✔✔For it to operate correctly, how should a Zener Diode be connected? - ✔✔Reversed
biased.
✔✔What is a BJT? - ✔✔Bi-polar Junction Transistor
✔✔What is a transducer? - ✔✔A device that converts energy from one form to another.
✔✔Explain how a fluorescent light produces a stroboscopic effect. - ✔✔The fluorescent
tube gives 100 flashes of light per second from the 50 Hz AC supply.
✔✔Identify the correct circuit - ✔✔The first step before isolating a circuit.
✔✔Prove-Test-Prove - ✔✔Ensures test instrument works before and after checking.
✔✔Lockout/tagout device - ✔✔Must be applied after switching off to prevent re-
energization.
✔✔Re-test your tester after proving dead - ✔✔To confirm the tester didn't fail during
testing.
✔✔PTP steps in order - ✔✔Prove tester → Test circuit → Prove tester again.
✔✔Cable management - ✔✔Important to reduce trip hazards and cable damage.
✔✔Poor housekeeping examples - ✔✔Tangled extension leads; liquids near live
equipment.
✔✔Fire tetrahedron elements - ✔✔Heat, fuel, oxygen, chemical chain reaction.
✔✔Safest extinguisher on energized electrical fire - ✔✔COI extinguisher.
,✔✔Fuse protection - ✔✔Protects the cable from overcurrent.
✔✔RCD trip current - ✔✔Typically trips at 30 mA.
✔✔PPE for electrical work - ✔✔Insulated gloves, safety glasses.
✔✔CAT IV meters - ✔✔Designed for utility connections and service entrances.
✔✔Earth bond test - ✔✔Used to verify continuity of protective earth conductors.
✔✔MEN stands for - ✔✔Multiple Earthed Neutral.
✔✔Safety advantages of MEN - ✔✔Effective fault current path; prevents dangerous
voltages.
✔✔MEN link location - ✔✔Found at the main switchboard.
✔✔Phase separation in a 3ph system - ✔✔120°.
✔✔Star-delta start method - ✔✔Reduces inrush current.
✔✔3ph motors efficiency - ✔✔Provide smoother torque and lower losses.
✔✔Capacitor-start motors - ✔✔Used for higher starting torque appliances like
compressors.
✔✔Shaded-pole motor - ✔✔Common in small fans.
✔✔NZ wiring rules standard - ✔✔AS/NZS 3000.
✔✔Portable appliance testing standard - ✔✔AS/NZS 3760.
✔✔Worker competency regulation - ✔✔Regulated by Electrical Workers Registration
Board (EWRB).
✔✔WorkSafe NZ responsibility - ✔✔Responsible for enforcing workplace safety
regulations.
✔✔Series circuit current - ✔✔The same through all components.
✔✔Power factor correction - ✔✔Improves efficiency and reduces reactive power.
✔✔Max volt drop for final subcircuits in NZ - ✔✔5% of nominal voltage.
, ✔✔TPS cable usage - ✔✔Used for fixed domestic wiring.
✔✔Flexible cords as fixed wiring - ✔✔Not mechanically protected or rated for
permanent installation.
✔✔Class I appliance requirement - ✔✔Must have protective earth connection.
✔✔Insulation resistance minimum value - ✔✔1 MΩ.
✔✔PAT testing frequency - ✔✔Depends on environment and appliance type.
✔✔Neutral conductor function - ✔✔Carries return current back to source.
✔✔Transformer function - ✔✔Changes voltage level (and current) via electromagnetic
induction.
✔✔Correct order to fight an electrical fire - ✔✔Disconnect power → Use COI or dry
powder.
✔✔RCD trip time at 30 mA leakage - ✔✔Should be under 300 ms (typical standard).
✔✔Personal protective grounding importance - ✔✔Prevents accidental energization or
shock.
✔✔What is the main focus of the EST topics that comprise approximately 70% of the
exam? - ✔✔Safety, including isolation, Prove Test Prove (PTP), workplace general
principles, fire safety, and extinguishers.
✔✔What are the components of fire safety mentioned in the EST study guide? - ✔✔Fire
tetrahedron and extinguishers.
✔✔What does 'MEN' refer to in the context of EST topics? - ✔✔MEN refers to Multiple
Earth Neutral systems and supply systems.
✔✔What types of motors are covered in the EST topics that make up approximately
70% of the exam? - ✔✔Three-phase motors.
✔✔What is the focus of the EST topics that comprise approximately 30% of the exam? -
✔✔Circuit theory, calculations, volt drop methods, single-phase motors, legislation, and
cable and cord types and uses.
