Electrical Glossary of Terms

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Electrical Glossary of Terms Written by Airway Group Team


Ampere – This is a unit of measurement for electrical current – it’s equal to the flow of one coulomb per second.


Central storage – Usually made up of batteries, this is electricity storage located on the domestic network, often near the Consumer Unit with other such equipment, such as a photovoltaic inverter (PV inverter).

Circuit breaker – A safety switch that automatically turns off the electricity supply in the event of a fault.

Consumer Unit – This piece of equipment takes the incoming mains supply and feeds it to individual domestic circuits.

Current – The flow of electricity through a conductor. This is measured in Amperes.


Distributed storage – Like, central storage, this usually consists of batteries, but it is distributed across the network – in phones, laptops and tablets, for example.


Efficacy – This is light output, measured in Lumens per watt (lm/W).

Electrical Installation Certificate – This denotes the person(s) who have designed and tested the electrical installation in question. Without a schedule of inspections, and the scheduling and record of any tests and results, the certificate is not complete.


Fuse – A specially-designed link that is designed to ‘blow’ under faulty conditions, preventing serious electrical faults, such as fires.


Kilowatt – One thousand watts of electricity.


Load – This is a generalised term that means anything that consumes electricity.


On-grid – Refers to a property – a domestic dwelling – that is connected to the national 230 V AC grid electricity supply.


Partial rewire – Where some wiring is replaced, whilst other sections of wire are kept.

PAT – Portable Appliance Testing: the regular testing of portable appliances to check that they are safe to use.

Protected circuit – Any electrical circuit that is protected from fire.


Unit of electricity – How electricity consumption is measured, typically in kilowatts per hour (kWh) or multiples of that measurement. This unit of measurement is often used for domestic electricity costing.


Voltage – An electromotive force that is measured in Volts.


Watt – A measure of power that is equivalent to one Joule per second. Used in correspondence with a circuit where the potential difference in the rate of consumption is one Volt and one current of one Ampere.