Electrical Glossary

More Details:

Unlike fuses which need replacing after one use, circuit breakers can be reset (either manually or automatically) to resume normal operation. They are essential components in modern electrical systems for ensuring safety and preventing damage to wiring and connected equipment.

More Details:

Safety switches are crucial for protecting against electric shock and electrocution. They detect when electricity is leaking to earth (such as through a person) and immediately cut the power supply. In Australia, RCDs are mandatory on all power point circuits in new homes and many existing circuits.

More Details:

Earthing is a critical safety measure that prevents electric shock by ensuring fault currents flow safely to earth rather than through a person. It also helps stabilise voltage levels and provides protection against lightning strikes and electrical surges.

More Details:

GFCIs are particularly important in areas where electrical circuits may be exposed to moisture, such as bathrooms, kitchens, and outdoor areas. They provide protection against electric shock and are required by electrical codes in wet locations.

More Details:

AFCIs detect the unique signatures of dangerous arcs that can occur in damaged wiring or loose connections. Unlike standard circuit breakers that only respond to overloads and short circuits, AFCIs can prevent fires caused by arc faults, which are a leading cause of electrical fires.

More Details:

Fuses consist of a metal wire or strip that melts when excessive current flows, preventing potential damage to electrical systems or fire hazards. Unlike circuit breakers, fuses are single-use devices that must be replaced after they operate. They're still used in some applications for their fast response time.

More Details:

Short circuits occur when active and neutral conductors make direct contact, allowing current to flow without passing through the intended load. This can cause dangerous heat buildup, sparks, and potential fires. Protective devices like circuit breakers and fuses are designed to quickly interrupt short circuits.

More Details:

Electrical faults include earth faults (current leaking to earth), short circuits (direct connection between active and neutral), and open circuits (broken connections). Faults can cause electric shock, fire, or equipment damage, which is why protective devices like RCDs and circuit breakers are essential.

More Details:

The switchboard (also called a distribution board or fuse box) is the heart of a building's electrical system. It receives incoming power and distributes it to individual circuits throughout the property. Modern switchboards include safety switches, circuit breakers, and surge protection devices.

More Details:

GPOs are designed to safely deliver power to a wide range of devices. Australian GPOs are rated for 230V and typically 10A or 15A current. They include safety features like shutters to prevent foreign objects from being inserted, and many modern GPOs include USB charging ports.

More Details:

Conductors are the pathways for electricity in all electrical systems. Copper is the most common conductor due to its excellent conductivity and durability. The size (cross-sectional area) of conductors determines how much current they can safely carry without overheating.

More Details:

Electrical insulation prevents electricity from flowing where it shouldn't, protecting people from shock and preventing short circuits. Common insulation materials include PVC, rubber, and XLPE. Insulation must be rated for the voltage and environmental conditions where it's used.

More Details:

Electrical cables consist of conductors (usually copper) surrounded by insulation and an outer protective sheath. Different cable types are designed for specific applications - from flexible cords for appliances to armoured cables for underground installation. Cable selection depends on current capacity, environment, and installation method.

More Details:

Transformers are essential for electricity distribution, stepping voltage up for efficient transmission over long distances, then stepping it down for safe use in homes and businesses. They work only with AC power and are found in everything from power grids to phone chargers.

More Details:

Capacitors can hold an electric charge temporarily and are used in various applications such as motor starting, power factor correction, and filtering in electronic circuits. They're essential in many electrical systems for energy storage, voltage smoothing, and timing functions.

More Details:

Inductors resist changes in current flow and are used in transformers, motor windings, and electronic filters. They're fundamental components in AC systems, creating magnetic fields that enable the operation of motors, transformers, and many electronic devices.

More Details:

Diodes have two terminals (anode and cathode) and are used for converting AC to DC, protecting circuits from reverse current, and controlling current flow. They're essential components in power supplies, battery chargers, and electronic control systems.

More Details:

Relays consist of an electromagnet that operates switch contacts when energised. They're used for controlling high-power circuits with low-power signals, providing safety isolation, and automatic switching in electrical systems. Common in motor control, lighting systems, and safety circuits.

More Details:

Ampacity depends on the conductor material, size, insulation type, installation method, and ambient temperature. Exceeding ampacity can cause dangerous overheating, fire hazards, and insulation damage. Proper ampacity calculation is crucial for safe electrical design.

More Details:

The neutral wire completes the electrical circuit by providing a return path for current. In Australian installations, neutral is connected to earth at the main switchboard. Neutral conductors should never be switched or fused, and proper neutral connections are crucial for safe operation.

More Details:

Active wires carry the voltage that powers electrical devices. In Australia, active wires are typically coloured red or brown in single-phase systems. These wires are dangerous when energised and should only be handled by qualified electricians with proper safety procedures.

More Details:

Polarity is essential for the proper operation of many electrical devices, particularly DC equipment, electronics, and some lighting systems. Incorrect polarity can cause malfunction, damage, or safety hazards. Always verify polarity when connecting electrical devices.

More Details:

Full-load current is critical for sizing conductors, circuit protection devices, and electrical infrastructure. It represents the steady-state current draw of equipment like motors, heaters, and transformers when operating at their nameplate ratings.

More Details:

AC is the standard form of electricity supplied to Australian homes and businesses at 50Hz frequency. The voltage alternates between positive and negative values in a sinusoidal pattern, making it efficient for long-distance transmission and easy to transform to different voltage levels using transformers.

More Details:

DC provides a constant voltage and current flow, making it ideal for electronic circuits, LED lighting, and energy storage systems. Solar panels generate DC power, which must be converted to AC through inverters for use with standard household appliances and to feed back into the grid.

More Details:

In Australia, the standard mains frequency is 50Hz, meaning the current completes 50 full cycles (positive to negative and back) each second. Frequency must remain stable for electrical equipment to operate properly, and deviations can cause motors to run incorrectly or electronic devices to malfunction.

More Details:

Named after Heinrich Hertz, this unit measures how often AC voltage completes a full cycle. Australian electrical systems operate at 50Hz, while some countries use 60Hz. The frequency affects the operation of motors, transformers, and timing circuits in electronic equipment.

More Details:

Three-phase power is more efficient than single-phase for distributing large amounts of electricity and running heavy machinery. It provides constant power delivery with less vibration in motors, making it ideal for industrial and commercial applications. Each phase carries the same frequency but peaks at different times.

More Details:

Single-phase power involves one alternating voltage distributed across two wires (active and neutral). In Australia, standard single-phase supply is 230V at 50Hz, sufficient for household appliances, lighting, and electronics. Most homes use single-phase power unless they have high-demand equipment.

More Details:

Voltage can be thought of as electrical 'pressure' that pushes current through circuits. In Australia, standard household voltage is 230V for single-phase and 400V for three-phase. Different appliances require different voltages - understanding voltage ratings is crucial for safety and proper equipment operation.

More Details:

Current is the actual flow of electricity through wires and devices. Higher current means more electrical flow, which can do more work but also generates more heat. Circuit protection devices like circuit breakers are rated by current to prevent dangerous overloads.

More Details:

Resistance depends on the material, length, cross-sectional area, and temperature of the conductor. Higher resistance means less current flow for the same voltage. Understanding resistance is fundamental for calculating current flow, power consumption, and heat generation in electrical circuits.

More Details:

Named after Georg Simon Ohm, the ohm is fundamental to electrical calculations. One ohm of resistance will allow one ampere of current to flow when one volt is applied across it. This relationship forms the basis of Ohm's Law, essential for all electrical design and troubleshooting.

More Details:

Ohm's Law is essential for electrical calculations and troubleshooting. It allows electricians to calculate any one of the three variables (voltage, current, or resistance) when the other two are known. This law applies to DC circuits and AC circuits with purely resistive loads.

More Details:

One watt equals one volt times one ampere in DC circuits or AC circuits with unity power factor. Watts indicate how much electrical energy is being used per second. Higher wattage devices consume more electricity and typically perform more work or generate more heat.

More Details:

Kilowatts are used for rating major appliances, electric vehicle chargers, solar systems, and whole-building electrical loads. Understanding kW ratings helps determine electrical requirements, circuit sizing, and energy costs. Most household appliances range from 0.1kW to 3kW.

More Details:

kWh is the standard unit for measuring electricity consumption on utility bills. For example, a 100W light bulb running for 10 hours consumes 1kWh. Understanding kWh helps calculate running costs and energy efficiency of electrical devices and systems.

More Details:

Power factor ranges from 0 to 1, with 1 being perfect efficiency. Poor power factor means more current is needed to do the same work, leading to higher electricity costs and strain on electrical systems. Power factor correction can improve efficiency, particularly in commercial and industrial settings.

More Details:

Active power is the 'real' power that runs motors, lights devices, and heats elements. It's the power component that shows on electricity bills and directly relates to the work being performed. In circuits with reactive components, active power is less than the total apparent power.

More Details:

Reactive power doesn't perform useful work but is necessary for the operation of inductive loads like motors and transformers. It oscillates between the source and load, contributing to apparent power but not energy consumption. Managing reactive power is important for power system efficiency.

More Details:

Apparent power represents the total electrical loading on a system, including both the useful (active) power and the non-working (reactive) power. It's important for sizing transformers, generators, and electrical infrastructure, as these components must handle the full apparent power.

More Details:

Impedance extends the concept of resistance to AC circuits, accounting for the effects of inductors and capacitors that cause phase shifts between voltage and current. It's measured in ohms and affects how much current flows in AC circuits for a given voltage.

More Details:

Inductive loads store energy in magnetic fields and release it back to the circuit, creating reactive power. This causes the current waveform to lag behind the voltage waveform, reducing power factor. Motors, transformers, and fluorescent light ballasts are common inductive loads.

More Details:

Capacitive loads store energy in electric fields and can provide reactive power to the circuit. This causes current to lead voltage, which can improve power factor when used to compensate for inductive loads. Capacitive loads are less common but include some electronic equipment and power factor correction capacitors.

More Details:

Resistive loads have a power factor of 1, meaning they use electrical energy most efficiently without creating reactive power. Common examples include electric heaters, incandescent light bulbs, and electric kettles. These loads convert electrical energy directly into heat or light.

More Details:

In Australia, mains electricity is typically 230V single-phase at 50Hz for residential properties. It's the primary power source for lighting, appliances, and electronics. Mains electricity is distributed through the electrical grid from power stations via transmission and distribution networks.

More Details:

Conduits protect electrical cables from physical damage, moisture, and environmental hazards. They also provide a means to safely route cables through buildings while maintaining accessibility for maintenance. Different conduit types are used for different applications and environments.

More Details:

Cable trays provide organised cable management for larger installations, allowing easy access for maintenance while supporting cable weight. They're commonly used in commercial buildings, data centres, and industrial facilities where many cables need to be routed together.

More Details:

Electrical circuits must form a complete loop for current to flow. Circuits include the power source, conductors (wires), loads (devices that use electricity), and often control devices like switches. Breaking the circuit at any point stops current flow.

More Details:

In parallel circuits, each component receives the full supply voltage, and if one component fails, current can still flow through other paths. This is the standard wiring method for household outlets and lights, ensuring that each device operates independently.

More Details:

In series circuits, the same current flows through all components, but voltage is divided across them. If one component fails, the entire circuit stops working. Series circuits are used in applications like Christmas lights and some electronic circuits.

More Details:

Open circuits can result from broken wires, loose connections, blown fuses, or open switches. They're a common fault condition that prevents electrical devices from operating. Finding and repairing open circuits is a fundamental electrical troubleshooting skill.

More Details:

Loads are anything that uses electricity to do work - lights, motors, heaters, electronics, etc. Understanding load requirements is crucial for properly sizing circuits, protective devices, and electrical infrastructure. Loads can be resistive, inductive, or capacitive.

More Details:

Load calculations consider all electrical devices, their power requirements, diversity factors, and safety margins. Accurate calculations ensure electrical systems can handle expected loads without overloading, preventing safety hazards and ensuring reliable operation.

More Details:

Maximum demand determines the capacity requirements for switchboards, cables, and protective devices. It's typically measured over 15 or 30-minute intervals and represents the peak loading condition that electrical systems must handle safely.

More Details:

Load factor indicates how consistently electrical power is used. A higher load factor suggests more efficient use of electrical infrastructure, with steady rather than highly variable power consumption. It's important for utility planning and energy cost management.

More Details:

Demand factor recognises that in most installations, not all electrical equipment operates at full capacity at the same time. This factor allows for more economical sizing of electrical systems while maintaining adequate capacity for normal operations.

More Details:

Diversity factor helps design more efficient electrical systems by recognising that different electrical loads typically reach their maximum demand at different times. This allows for more economical sizing of distribution equipment and infrastructure.

More Details:

Utilisation factor helps assess equipment efficiency and capacity planning. High utilisation indicates equipment is well-used and cost-effective, while low utilisation might suggest oversizing or underuse of electrical infrastructure.

More Details:

Electrical tape is typically made from PVC or vinyl and is designed to stretch and conform to irregular shapes. It provides electrical insulation, mechanical protection, and environmental sealing for electrical connections. Different types are available for various voltage ratings and environmental conditions.

More Details:

AS/NZS 3000, commonly called the 'Wiring Rules', is the primary standard governing electrical installations in Australia and New Zealand. It covers everything from basic safety requirements to complex installation methods, ensuring electrical work meets minimum safety standards.

More Details:

Compliance certificates are required for most electrical work in Australia, providing proof that installations meet safety standards and building codes. They're essential for insurance, property sales, and regulatory compliance. Only licensed electricians can issue these certificates.

More Details:

Licensed electricians have completed formal training, apprenticeships, and ongoing education to ensure they can safely install, maintain, and repair electrical systems. In Australia, only licensed electricians can perform most electrical work and issue compliance certificates.

More Details:

Test and Tag involves visual inspection and electrical testing of portable appliances to ensure they're safe to use. Testing includes checks for damaged cords, earth continuity, insulation resistance, and polarity. It's mandatory in many workplaces and rental properties.

More Details:

Insulation resistance testing uses high voltage (typically 500V or 1000V) to test if insulation can prevent current leakage. This testing helps identify deteriorated insulation before it becomes dangerous, and is required during electrical installations and periodic safety inspections.

More Details:

Safety inspections involve visual checks, testing of protective devices, thermal imaging, and verification of earthing systems. They're recommended periodically for all properties and are essential when buying/selling property or after electrical modifications.

More Details:

Ammeters are essential tools for electrical diagnostics and maintenance, available in both analogue and digital forms. They're used to verify proper current flow, diagnose faults, and ensure electrical systems operate within safe limits. Ammeters must be connected in series with the circuit being measured.

More Details:

Smart home systems can control lighting, power outlets, security systems, and major appliances through smartphones or voice commands. They can improve energy efficiency, convenience, and security while requiring proper electrical infrastructure and network connectivity.

More Details:

Solar systems include photovoltaic panels, inverters, mounting systems, and safety disconnects. They can reduce electricity bills and environmental impact while requiring proper electrical integration with existing home wiring and utility connections.

More Details:

EV charging stations range from basic wall-mounted units (Level 1 & 2) to fast DC chargers. Home installations typically require dedicated circuits, upgraded electrical panels, and proper safety equipment. Installation must comply with electrical codes and local regulations.

More Details:

Surge protection includes devices installed at the main electrical panel (Type 1 & 2) and individual outlets (Type 3). They divert excess voltage safely to earth, protecting sensitive electronics from damage. Whole-home surge protection is increasingly important with modern electronic devices.