Electrical switchgear: what is it and what components does it consist of?

Electrical switchgear, or switchgear, comprises a wide range of essential devices to ensure the efficient operation of the network

The infinite number of devices that, unnoticed by us, act in our daily lives to guarantee our electricity supply is overwhelming if we think about it carefully. This set of elements is commonly called electrical switchgear—electrical equipment or switchgear in some Spanish-speaking countries—and represents a tangle of perfectly interconnected systems that are present in the journey of electrical energy from its generation, through its distribution, and ending with its subsequent consumption at its destination. However, despite its crucial role in making something wonderful something everyday, we are unaware of what elements make up this switchgear or how they interact with each other. Today we want to remedy this by explaining this and other things. Let’s go for it.

As we said, electrical switchgear could be defined as the set of devices – with different levels of technological development – that control, command, measure, protect, transform and distribute electrical energy in a safe and efficient manner, guaranteeing through their particular role that our homes, workplaces, industries, critical infrastructures, transport systems or power generation plants can function completely normally. These unknown elements, which can be installed outdoors or indoors depending on where they are located and their functions, are what guarantee that the electrification of society becomes a reality, also favoring the insertion of renewable energies in our fight against climate change. Behind every volt with which we turn on the light, power our appliances, charge our electric vehicle, or ensure the preservation of our food, there is a technological device that makes it all possible.

These systems are found distributed throughout our landscapes: cables that cross our fields to carry energy to cities, substations that populate the outskirts of industries or towns, prefabricated concrete transformation centers on and under our sidewalks, low-voltage panels close to our homes… In short, a whole world of elements that together represent one of the greatest technological wonders of our time and that allowed the second industrial revolution and the formation of our current society.

How are the elements of electrical switchgear classified?

We can divide electrical switchgear according to the following classifications:

Switchgear and type of function

• Switching: connection and opening devices (disconnectors, switches, contactors, etc.).
• Protection: systems that guarantee the operation of the rest of the elements, preventing power outages (fuses, circuit breakers, etc.).
• Measuring: equipment that calculates electrical consumption (meters).
• Regulation: adapts the electricity conditions to the consumption requirements (low voltage panels).
• Control: manual, automatic or remote handling systems (relays).
• Reactors and capacitors

Switchgear and voltage level

• Low voltage (LV): ≤ 1,000 V a.c., ≤ 1,500 V d.c.
• Medium voltage (MV): From 1 to 36.5 kV (Can reach 45 kV)
• High voltage (AT): From 45 to 220 kV
• Very High Voltage (HV): >220 kV

Switchgear according to its location

• Interior assembly: the elements are located inside a sheltered place (a building, a prefabricated concrete and/or sheet metal structure, etc.), protected from external environmental factors such as water, cold, heat…
• Outdoors: the installation takes place outdoors so that the devices are prepared to be exposed to climatic factors. An example is wiring, voltage towers or pole transformers.

Switchgear according to its protection

• Not protected or open: devices whose structure does not have a cover.
• Protected with a metal enclosure: they have a cover to guarantee their useful life.

Uses of switchgear 

• Domestic installations: Lighting systems, power outlets, appliances, security systems, among others.
• Industrial installations: Used to control machinery, automation systems, power distribution to large equipment, circuit protection, among other industrial applications.
• Public installations: Used in public lighting, transportation systems, power supply to public buildings, among others.
• Networks electrical: Their functions are to support the generation, production, storage, distribution, control or transformation of electrical energy.

What elements make up the electrical switchgear?

As such, the electrical switchgear is made up of a wide variety of elements such as such as low voltage panels, transformers, wiring, energy meters…

Let’s look at some of the most important ones:

• Wiring: The quintessential electricity conducting element that we can find in underground or visible lines between towers and poles.
• Electrical transformers: They are used to transform electricity values ​​according to consumption needs.
• Cells or switches: These perform line, protection and/or measurement switch functions.
• Low voltage switchboard: These adapt the electricity to the specific uses of the final consumption points.
• Transformation centers: These bring together, as a whole under a prefabricated concrete or metal enclosure, different elements such as those mentioned above; offering a comprehensive solution.
• Meters: Their function is crucial to measure the level of consumption of electricity end users.

• Control and protection elements: They serve as the brain of the electrical network, in communion with the rest of the elements, and allow the automation and remote management of the network.

This is why the design of the elements themselves and the configuration of the electrical switchgear as a whole makes it possible to guarantee a reliable supply.

Digitization and automation as guarantees for the future of the equipment electric

In this sense, the present and future of switchgear depends on ensuring its digitalization and automation. A concept that, Jose María Torres, director of the Smart Grids division at Ormazabal, defines as “a primary objective to achieve the decarbonization goals established by the European Union”. Torres maintains that exogenous and current geopolitical factors “have accelerated the transformation of the electricity industry towards a world with greater integration of renewable and more sustainable generation”. Something on which “the European Commission and the Spanish Government, through the PNIEC, are aligned in the pursuit of a global shift toward sustainability; an objective shared by companies in the electricity sector.”