Switchgear
Switchgear is a general term used to refer to a range of switches, circuit breakers, fuses, etc., which are used in an electric power system to control, regulate and switch the circuit on and off. By controlling the circuit, switchgear protects and isolates electrical equipment from the power supply, enabling testing, maintenance and fault clearing work to be undertaken.
Switchgear has two types of components:
- Power-conducting components: These conduct or interrupt the power flow; such as switches, circuit breakers, fuses, isolators, relays, lightning arrestors, and so on.
- Control systems: These monitor, control and protect the power-conducting components; such as control panels, current transformers, potential transformers, associated circuitry, and so on.
Although the circuit breaker is the main component, it is the combination of equipment within the switchgear enclosure that allows high voltage currents to be interrupted.
Switchgear is directly linked to the supply system and, based on the voltage level, can be classified as either:
- Low voltage switchgear (LV).
- Medium voltage switchgear (MV).
- High voltage switchgear (HV).
Switchgear can be a simple open-air isolator switch or can be insulated in another substance such as oil, pressurised sulphur hexafluoride gas, or insulated in a vacuum.
Lower voltage switchgear can be enclosed within a building, however, higher voltages (approximately over 66 kV) usually require the switchgear to be externally mounted and insulated by air.
[edit] Find out more
[edit] Related articles on Designing Buildings Wiki
Featured articles and news
The UK's Modern Industrial Strategy: A 10 year plan
Previous consultation criticism, current key elements and general support with some persisting reservations.
Building Safety Regulator reforms
New roles, new staff and a new fast track service pave the way for a single construction regulator.
Architectural Technologist CPDs and Communications
CIAT CPD… and how you can do it!
Cooling centres and cool spaces
Managing extreme heat in cities by directing the public to places for heat stress relief and water sources.
Winter gardens: A brief history and warm variations
Extending the season with glass in different forms and terms.
Restoring Great Yarmouth's Winter Gardens
Transforming one of the least sustainable constructions imaginable.
Construction Skills Mission Board launch sector drive
Newly formed government and industry collaboration set strategy for recruiting an additional 100,000 construction workers a year.
New Architects Code comes into effect in September 2025
ARB Architects Code of Conduct and Practice available with ongoing consultation regarding guidance.
Welsh Skills Body (Medr) launches ambitious plan
The new skills body brings together funding and regulation of tertiary education and research for the devolved nation.
Paul Gandy FCIOB announced as next CIOB President
Former Tilbury Douglas CEO takes helm.
UK Infrastructure: A 10 Year Strategy. In brief with reactions
With the National Infrastructure and Service Transformation Authority (NISTA).
Ebenezer Howard: inventor of the garden city. Book review.
The Grenfell Tower fire, eight years on
A time to pause and reflect as Dubai tower block fire reported just before anniversary.
Airtightness Topic Guide BSRIA TG 27/2025
Explaining the basics of airtightness, what it is, why it's important, when it's required and how it's carried out.
Construction contract awards hit lowest point of 2025
Plummeting for second consecutive month, intensifying concerns for housing and infrastructure goals.
Understanding Mental Health in the Built Environment 2025
Examining the state of mental health in construction, shedding light on levels of stress, anxiety and depression.
The benefits of engaging with insulation manufacturers
When considering ground floor constructions.
Lighting Industry endorses Blueprint for Electrification
The Lighting Industry Association fully supports the ECA Blueprint as a timely, urgent call to action.
Comments