Electrical Glossary
RCBO (Residual Current Breaker with Overcurrent Protection)
Last Updated: April 25, 2025RCBO: A protective device that combines RCD and circuit breaker functions. It protects against earth leakage and overcurrent in one unit.
Isolator Switch
Last Updated: April 25, 2025Isolator Switch: A manual switch used to disconnect power during maintenance or emergencies, ensuring complete circuit isolation.
Surge Protector
Last Updated: April 25, 2025Surge Protector: A device that shields electrical appliances from voltage spikes by diverting excess current to earth.
Weatherproof Socket
Last Updated: April 25, 2025Weatherproof Socket: An outdoor-rated GPO or switch designed to resist water and dust, typically with an IP rating of IP53 or higher.
Earth Clamp
Last Updated: April 25, 2025Earth Clamp: A device used to securely connect an earth conductor to a ground rod or pipe, ensuring effective earthing.
GPO (General Power Outlet)
Last Updated: April 25, 2025GPO: A standard wall socket for connecting appliances. GPOs are commonly installed throughout Australian homes and buildings.
Lug
Last Updated: April 25, 2025Lug: A connector used to attach cables to electrical terminals, allowing for secure, conductive connections.
Busbar
Last Updated: April 25, 2025Busbar: A metallic strip or bar used for distributing power within switchboards and panels, often made from copper or aluminium.
Electrical Enclosure
Last Updated: April 25, 2025Electrical Enclosure: A protective box or cabinet used to house electrical equipment and prevent exposure to the environment.
DIN Rail
Last Updated: April 25, 2025DIN Rail: A metal rail standard used to mount circuit breakers and control equipment inside switchboards and electrical enclosures.
Terminal Block
Last Updated: April 25, 2025Terminal Block: A modular connector that safely joins multiple wires in an electrical panel or enclosure.
Earth Rod
Last Updated: April 25, 2025Earth Rod: A metal rod driven into the ground to provide a low-resistance path for fault currents to earth. Common in earthing systems.
Cable Tray
Last Updated: April 25, 2025Cable Tray: A rigid support system for safely carrying electrical cables in large installations, especially commercial or industrial.
Conduit
Last Updated: April 25, 2025Conduit: A protective tube used to route and protect electrical wiring in both commercial and domestic installations.
Transformer
Last Updated: April 25, 2025Transformer: A device that changes voltage levels in an electrical circuit. Used to step voltage up or down for safe transmission and use.
Contactor
Last Updated: April 25, 2025Contactor: An electrically-controlled switch used to control high-current circuits, often used in lighting, heating, and motors.
Fuse
Last Updated: April 25, 2025Fuse: A single-use safety device that breaks the circuit when too much current flows, protecting wiring and devices from damage.
Safety Switch
Last Updated: April 25, 2025Safety Switch: A common term in Australia for an RCD, designed to protect people from electrical shock by shutting off power during a fault.
Residual Current Device (RCD)
Last Updated: April 25, 2025RCD: A life-saving safety switch that quickly cuts off electricity if it detects a current leak to earth, helping prevent electrocution.
Circuit Breaker
Last Updated: April 25, 2025Circuit Breaker: A protective device that automatically interrupts power flow when excessive current is detected. It helps prevent electrical fires and equipment damage.
Earthing
Last Updated: April 25, 2025Earthing: In Australia, earthing refers to connecting the neutral point of an electrical system to the earth to ensure safety and regulatory compliance. The MEN (Multiple Earthed Neutral) system is standard in QLD and across the country.
Grounding
Last Updated: April 25, 2025Grounding: A protective measure where parts of an electrical system are connected to the earth to prevent electrical shock or fire in case of faults. Grounding provides a safe path for fault currents and stabilises voltage levels.
Open Circuit
Last Updated: April 25, 2025Open Circuit: A break in an electrical path that prevents current from flowing. This could be due to a switch being off, a wire being cut, or a component failing. Open circuits are the opposite of short circuits.
Short Circuit
Last Updated: April 25, 2025Short Circuit: An unintended low-resistance path in a circuit that allows excessive current to flow. It can cause fires, equipment damage, or tripped breakers. Proper circuit design and protection devices are essential to prevent short circuits.
Electromotive Force (EMF)
Last Updated: April 25, 2025Electromotive Force (EMF): The voltage generated by a power source like a battery or generator. It is the driving force that pushes electrons through a circuit, producing current flow.
Hertz (Hz)
Last Updated: April 25, 2025Hertz (Hz): The unit of frequency, representing cycles per second. In Australia, the standard frequency of AC power supply is 50 Hz. This means the current changes direction 50 times per second.
Inductance
Last Updated: April 25, 2025Inductance: The property of a conductor by which a change in current induces a voltage (EMF). It’s measured in henrys (H) and used in coils, transformers, and motors. Inductance is vital in managing current flow in AC circuits.
Capacitance
Last Updated: April 25, 2025Capacitance: The ability of a system to store an electric charge, measured in farads (F). Capacitors are components that temporarily store energy and are used in power supply filtering, motor starting, and signal processing.
Conductivity
Last Updated: April 25, 2025Conductivity: The ability of a material to conduct electric current. High conductivity materials like copper and aluminium are commonly used in electrical wiring. It is the reciprocal of resistivity and impacts efficiency and safety.
Impedance
Last Updated: April 25, 2025Impedance: A combination of resistance and reactance in AC circuits. It represents the total opposition to current flow and is measured in ohms (Ω). Impedance affects how current flows through complex circuits and is key in audio, RF, and motor applications.
Electrical Load
Last Updated: April 25, 2025Electrical Load: Any device or component that consumes electric power in a circuit. Loads can be resistive (like heaters), inductive (like motors), or capacitive. Understanding load types helps in designing and balancing circuits.
Power Factor
Last Updated: April 25, 2025Power Factor: The ratio of real power (watts) used to do work and apparent power (volt-amperes) in a circuit. A low power factor indicates inefficient energy usage. Managing power factor is crucial in industrial setups to reduce energy costs and avoid utility penalties.
Amperage
Last Updated: April 25, 2025Amperage: The strength of an electrical current, measured in amps (A). It reflects how much electricity is flowing and influences the size of conductors and protective devices required for safety and performance.
Wattage
Last Updated: April 25, 2025Wattage: The measure of electrical power, calculated as voltage multiplied by current (W = V × I). Wattage determines the rate at which electrical energy is used or generated. It is critical for understanding power consumption in residential and commercial settings.
Ohm’s Law
Last Updated: April 25, 2025Ohm’s Law: A basic electrical principle stating that voltage (V) equals current (I) times resistance (R): V = I × R. This law is used to calculate the relationship between voltage, current, and resistance in a circuit, making it a core formula in electrical work.
Resistance
Last Updated: April 25, 2025Resistance: The opposition to the flow of current in an electrical circuit, measured in ohms (Ω). Materials with high resistance convert more electrical energy into heat. It’s a fundamental concept used in designing safe and effective circuits.
Current
Last Updated: April 25, 2025Current: The flow of electric charge through a conductor, measured in amperes (amps). It represents how much electricity is flowing through a circuit. Current can be either AC or DC and is essential for operating electrical devices and systems.
Voltage
Last Updated: April 25, 2025Voltage: Also known as electric potential difference, voltage is the “pressure” that pushes electrical current through a circuit. Measured in volts (V), it determines how much energy is carried by the current. In Australia, the standard domestic supply is 230V AC.
Direct Current (DC)
Last Updated: April 25, 2025Direct Current (DC): A unidirectional flow of electric charge, typically supplied by batteries or solar panels. DC is essential in electronics, electric vehicles, and for charging devices like phones and laptops. It doesn’t change direction like AC and is often converted via inverters or rectifiers.
Alternating Current (AC)
Last Updated: April 25, 2025Alternating Current (AC): A type of electrical current where the direction of flow reverses periodically. It is the standard form of electricity supplied to homes and businesses in Australia. AC is ideal for long-distance transmission and is used for powering appliances, lighting, and HVAC systems.