WorksheetsHigh Voltage Areas
Total questions: 15
Worksheet time: 11mins
What is the definition of high voltage as given by the Electricity (Safety) Regulations 2010?
What is the definition of low voltage as given by the Electricity (Safety) Regulations 2010?
A voltage not exceeding 50 volts AC or 120 volts ripple-free DC, but not exceeding 1000vAC or 1500VDC.
A voltage not exceeding 100 volts AC or 200 volts ripple-free DC but not exceeding 3000vAC or 1600VDC.
A voltage not exceeding 10 volts AC or 20 volts ripple-free DC but not exceeding 1200vAC or 2500VDC.
A voltage not exceeding 500 volts AC or 1000 volts ripple-free DC but not exceeding 1050vAC or 1050VDC.
Why does equipment operating at high voltage require greater insulation and clearance distance than low voltage equipment?
To make trained persons feel confident working around HV.
HV can enhance insulation in equipment and cause greater seperation.
HV can break down insulation/equipment and cause them to be conductive, including the air.
To stop people from working on it.
Which four (4) of these are primary dangers of working in high voltage areas?
Temporary Blindness, Vertigo, Stress & Cuts
Electric Shock, Arc Flash, Fire & Burns
Exhaustion, Static Shocks, Radiation & Fractures
Loud Noises, Workplace Disagreements, Poor Diet & Concussion
In regards to high voltage areas, what does M.A.D stand for?
Maximum Arc Distance
Maximum Approach Distance
Minimum Arc Distance
Minimum Approach Distance
Which of the following is true about Touch Voltage?
It only happens if the person is standing on a wet surface.
It happens regardless of whether the person is wearing wet or dry clothing or standing on a wet or dry surface.
It only happens if the person is wearing insulated gloves and boots.
Which of these statements describes "Step Voltage" in HV Works?
It is Potential Difference created by decreasing voltage radiating from a fault in the ground .
It is the voltage created by moving quickly on a static surface.
A shock that makes you step funny until you recover.
What is Clearance Distance?
Prevention of rodent damage in HV gear
How far workers should be from each other
An insulator surface that prevents tracking
An air gap that prevents arcing
What is Creepage Distance?
Prevention of rodent damage in HV gear
How far workers should be from each other
An insulator surface that prevents tracking
An air gap that prevents arcing
Which two [2] of these are dangers of working around high voltage equipment?
High voltage equipment and electrical systems can generate heat and sparks, which can cause a fire to start.
High voltage moving machinery produces excessive noise.
Electric shock when a person comes into contact with (or close to) live electrical wires or equipment.
Arc flash due to excessive creepage distance.
Induced voltages resulting in burns to the hands.
An electrical worker is working on 11kV equipment.
Why should they be concerned about high voltages?
They could exceed the rupturing capacity of the HRC fuse.
Rapid variations in high voltage currents could vibrate the terminations loose.
High voltage transformers can produce excessive noise and result in temporary hearing loss.
They could induce currents into de-energised conductors resulting in an electric shock.
A Distribution Line Mechanic is planning to work on a power pole, which has LV and HV lines.
Which of these documents should they refer to for guidance?
ECP 34.
ASNZS 3000: 2007.
ECP 50.
Electricity Act.
Which two [2] of these safety precautions must be taken when working around HV equipment?
Wear lightweight footwear.
Ensure minimum approach distances.
Use aluminium ladders.
Wear appropriate PPE.
Terminate the cables together to avoid inadvertent livening.
Why are touch voltages more dangerous than step voltages?
Fault current is very high.
Fault current will flow through the heart.
Everything you touch can become live.
Touch voltage is higher than step voltage.
Why would a Distribution Line Mechanic apply portable earths to HV lines?
To ensure the fault current remains low enough to activate the protective device.
To ensure neutral to earth remains 0V.
To keep the worksite tidy.
To keep the line at earth potential in case of inadvertent livening.
