Cert III Electrician flashcards
Cert III Electrician · Build recall with a focused review session.
32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Hierarchy of control
- The ranked order for managing risk: eliminate, substitute, isolate, engineer, administer, then use PPE. Controls higher in the list are more reliable because they do not depend on human behaviour.
- Test before touch
- The isolation procedure: identify, isolate, lock and tag, prove the tester on a known live source, test for dead on all conductors, then re-prove the tester.
- Arc flash incident energy
- The thermal energy released by an arcing fault at a given working distance, expressed in calories per square centimetre. It determines the arc-rated clothing category required.
- Primary duty of care
- The obligation on a person conducting a business or undertaking to ensure the health and safety of workers and others so far as is reasonably practicable.
- Notifiable incident
- A death, serious injury or illness, or dangerous incident such as an electric shock or structural collapse that must be reported to the WHS regulator immediately.
- Hazardous waste segregation
- Separating mercury lamps, batteries, contaminated absorbents and oils from general waste so each stream is collected and disposed of through a licensed recycler.
- Ohm's law and power
- V equals I times R. Power P equals V times I, which also equals I squared times R or V squared divided by R.
- Capacitive reactance
- Xc equals one divided by two pi f C. It falls as frequency rises, so capacitors pass high frequencies and block DC.
- Power factor
- The ratio of real power to apparent power, equal to cos phi and to R divided by Z. A low value means more current for the same useful power.
- Three-phase star relationship
- In a star connection the line voltage equals root three times the phase voltage, while the line current equals the phase current.
- Voltage drop limit
- AS/NZS 3000 limits voltage drop to five percent from the point of supply to any point of installation for low-voltage consumers.
- Protective device coordination
- The design current must not exceed the device rating, the device rating must not exceed cable capacity, and the device must clear overloads before cable damage.
- Cable derating factors
- Correction factors applied to base current-carrying capacity for ambient temperature, grouping, thermal insulation and installation method, as tabulated in AS/NZS 3008.1.1.
- IP rating digits
- The first digit rates protection against solids from zero to six; the second rates protection against liquids from zero to eight. IPX4 means splash-resistant.
- Equipment protection class
- Class I relies on protective earthing; Class II is double-insulated without an earth; Class III operates at safety extra-low voltage.
- Luminous efficacy
- The light output in lumens divided by the electrical power in watts. LED lamps typically reach 80 to 150 lumens per watt.
- Synchronous speed
- Ns equals 120 times frequency divided by the number of poles. A four-pole motor on 50 hertz has a synchronous speed of 1500 rpm.
- Star-delta starting
- A starting method that connects the motor windings in star for starting, reducing current and torque to one third, then switches to delta for running.
- Seal-in contact
- A normally open auxiliary contact wired in parallel with the start button so the contactor coil stays energised after the button is released.
- Insulation resistance test
- A DC test at 500 volts between conductors and earth. The measured resistance must be at least one megohm for a low-voltage installation.
- Earth fault loop impedance
- The total impedance of the fault path from the point of fault back to the supply transformer. It determines whether the protective device disconnects within the required time.
- RCD trip test
- Verification that the device does not trip at half rated residual current, trips within the specified time at rated current, and trips quickly at five times rated current.
- MEN system
- Multiple earthed neutral: the neutral is earthed at the supply transformer and again at the installation main earthing point, keeping fault loop impedance low.
- Certificate of compliance
- A legal document issued by the licensed electrician confirming that the electrical work performed complies with the Wiring Rules and relevant standards.
- AS/NZS 3012
- The standard for electrical installations on construction and demolition sites, covering temporary supplies, leads, and inspection and testing of portable equipment.
- Single-line diagram
- A simplified drawing showing the electrical distribution from supply through main switchboard, sub-boards and protective devices, with each circuit represented by one line.
- As-built drawings
- The final drawings updated to show the installation as actually constructed, including all variations, issued to the client at project handover.
- Cable schedule
- A table listing each cable's size, type, length and route, used for procurement and installation and reconciled against the drawing set.
- Job safety analysis
- A documented pre-work process that breaks the task into steps, identifies hazards for each step, and records the controls before work begins.
- Anti-islanding protection
- A function of grid-connected inverters that disconnects the solar array from the network when the grid supply is lost, protecting workers during outages.
- Coefficient of performance
- The ratio of heat delivered to electrical energy consumed by a heat pump. Values of three to five mean far less energy than resistive heating.
- Power factor correction
- Adding switched capacitors to supply reactive power locally, reducing the current drawn from the supply and lowering demand charges on the electricity account.