Glossary of Electrical Terms

For homeowners and businesses in Melksham, Wiltshire, and surrounding areas.

Talking Shop – Electricity on Your Terms

When we come to install a new electrical system on your property in Wiltshire, make electrical repairs or carry out any other sort of electrical work, you may hear us “talk shop” and wonder what it’s all about! We hope our A-Z Glossary of Electrical terms will help shine a light on what we are saying.

There are also occasions when it is handy for our customers to know some basic terms so that you can explain what’s going wrong with your electrics, for your safety’s sake in the event of an electrical fault, or just to satisfy your own curiosity in an increasingly power-hungry world.

Speaking “electric” is not a requirement by any means, but we hope you’ll find this glossary interesting and useful:

Glossary of Electrical Terms

Although we take on any and all electrical projects in Melksham and the suburbs of Bowerhill, The Spa and Sandridge we are the local specialists in LED lighting installations.

LED (light emitting diode) technology is environmentally friendly and energy efficient, and many of our commercial and residential customers are switching their lighting systems from traditional incandescent to LED in Melksham.

We’re also experts at electrical fault-finding in Melksham, and offer affordable Planned Preventive Electrical Maintenance contracts for local businesses who want to keep their premises electrically efficient and hazard free. Regular electrical testing and inspections help to ensure that potential faults don’t escalate into expensive repairs.

We are highly experienced in industrial and commercial electrics in Melksham and are Part P certified electrical contractors in Melksham.

As registered electricians you can be confident that our work is regularly assessed, that we work to the BS7671 safety standard, and that we are insured for your protection.

AC is a type of electrical current in which the direction of the flow of electrons switches back and forth at regular intervals or cycles. It is the standard type of current used in electrical distribution systems by utility power companies because it travels easily through cabling. (See Direct Current, which is the opposite).

A unit of measure of the rate of electrical flow along a wire (or other conductor).

The product of voltage and current in an AC circuit. It is the total power required to operate a device, including both active power and reactive power.

An electrical explosion, producing light and heat, that occurs when a large amount of current flows through the air to cross a small gap between two conductors.

A complete path (or loop) through which electric current can flow continuously.

A material that allows electric current to flow through it with little resistance.

The main electrical distribution board in a domestic property – formerly known as a fuse board.

A type of current that flows in one direction only. (See Alternating Current above, which is the opposite.)

A conductor that connects to the ground. It provides a safety path for electric current to flow in the event of a fault, protecting you from electric shock.

Also known as an Overcurrent Protective Device (OCPD) this is a safety device which breaks the flow through a circuit when there is too much current flowing through it. It works by containing a metal strip that melts and breaks the contact, preventing an electrical fire and damage to equipment.

A safety device that guards against accidental electrocution by monitoring the current travelling to and from an electrical load.

A type of cable made of polypropylene which does not produce dangerous toxic gas or acid if in a fire.

A term that covers a variety of non-conductive materials that prevent or reduce the flow of electric current.

A unit of apparent power (see above), which describes the total amount of power being used by a system. It is equal to 1000 volt-amperes.

A measure of how much power an electric appliance consumes, consisting of 1,000 watts.

A semiconductor device that emits light when an electric current flows through it, generally used to provide very energy-efficient lighting.

The blue strand in the cable that connects an electrical appliance to a three pin plug is the neutral wire, designed to complete the circuit from the appliance back to the supply.

The ohm is a unit for measuring electrical resistance between two points of a conductor when a constant potential difference of one volt is applied to these points.

A safety device that protects a circuit from excessive current. Fuses (see above) and circuit breakers are both examples of OCPDs.

An electrical phase is the way the power load is distributed. In the UK the mains supply to homes is usually a single phase AC current, as opposed to a 3-phase power supply which is used in high demand situations like commercial and industrial buildings.

The power factor of an AC circuit is a measure of how efficiently and effectively your electrical circuit is using the available power. In a perfect world to minimise power wastage the Power Factor of a circuit should be between 0.95 and 1.

Measured in volt-amperes reactive (VAR) reactive power is the dissipated power that results from inductive and capacitive loads. Also known as “phantom power” it is required to operate some types of electrical equipment like motors and transformers.

The measure of the amount of hindrance to the flow of electric current through a conductor.

Also known as an RDB (Residual Current Breaker) or RCD (Residual Circuit Breaker) this is a safety device that disconnects a circuit as soon as it detects a current leak to the earth wire.

This is a type of electrical circuit that is commonly used in homes in the UK. In a ring circuit the live, neutral and earth wires form a loop of cable that run from the consumer unit to all the sockets in turn, then back to the consumer unit.

Voltage is the term used to describe the pressure from an electrical power source that pushes charged electrons (electrical current) through a conducting loop, to flow into an appliance (such as a lamp) and cause it to work. Voltage is measured in volts.

Named after Scottish mechanical engineer James Watt, who invented the steam engine which drove the Industrial Revolution, this is a unit of measurement for the rate at which energy is consumed by an item, and how much it needs to function. For example keeping the oven on for half an hour consumes on average 2,000 watts of power.

Get in touch to discuss your requirements.

This is by no means a complete list of all electrical terms, but it covers some of the most common ones you’ll hear in the UK.

As qualified, experienced NAPIT registered electricians in Wiltshire we at Invisiwire are always happy to help if you have an electrical conundrum or need any help and advice about an electrical problem.