What Is Switchgear? Components, Types, and How It Works

Key Takeaways:

Switchgear is a system containing several electrical components, and it is used to regulate electricity flow, protect it from power outages, and cut off electricity flow when a power failure occurs.
Switchgear’s main components include circuit breakers, relays, fuses, disconnect switches, and control panels.
Types of switchgear include low-voltage switchgear, medium-voltage switchgear, high-voltage switchgear, air-insulated switchgear, and gas-insulated switchgear.

In the industry, electrical systems need proper monitoring, from electrical installation to maintenance, since a malfunction could risk equipment damage and operational loss.

Switchgear is an important component for managing the system’s safety and robustness. So, what actually is switchgear? What are its components and types? Find the answer in the explanation below!

What Is Switchgear?

Switchgear is a collection of electrical devices within an enclosure box. The switchgear functions include:

Controlling the flow of electricity: It allows the operator to turn the electric supply on or off safely and based on the needs.
Protecting from electrical faults: Cuts off the electrical circuit automatically when a fault occurs, such as a short circuit, power surge, or overload.
Isolating a certain system: Separates certain parts from the electrical network for maintenance or repair purposes without disturbing other parts of the system.

Switchgear is very important, especially for facilities that are at high risk of electrical faults or high maintenance, such as industrial factories, power plants, and water treatment facilities.

Switchgear Components

Switchgear can run the functions mentioned above with the support of several components:

Circuit breaker: Cuts the flow of electricity automatically when a fault occurs to protect the equipment and personnel.
Relay: Monitors the electrical parameters, detects faults, and launches protection mechanisms when abnormal conditions occur.
Fuse: A ready-to-melt component that works to cut off the electrical circuit when the electrical flow goes beyond the safety limit.
Disconnect switch: Isolates the equipment physically from the electrical sources for safe maintenance and repair.
Control panel: Observes and controls the overall switchgear operations.

How Switchgear Works

Switchgear operates under two conditions: normal and fault conditions. Here is a brief explanation:

1. Normal Condition

Under normal conditions, the circuit breaker is closed, allowing electricity to flow from the source to the load through the switchgear. The switchgear continuously monitors voltage, current, frequency, and power factor to ensure operational parameters stay within predetermined limits.

2. Fault Condition

When a fault occurs, the relay can detect the condition within milliseconds and send a trip signal to the circuit breaker. This signal opens the circuit breaker contacts, interrupting the current and isolating the faulted section. An electric arc may emerge if the contacts separate while the current is still flowing, but it can be put out with certain substances, such as oil or air.

Types of Switchgear

Based on the voltage level handled and its technology or insulating medium, switchgear is divided into the following several types:

1. Low-Voltage (LV) Switchgear

LV switchgear operates at low voltage (a maximum of 1,000 volts, or 1 kV). This type of switchgear is commonly used in residential buildings, commercial buildings, and small- to medium-scale industries.

2. Medium-Voltage (MV) Switchgear

MV switchgear handles voltages between 1 kV and 36 kV. You can find it in industrial plants, infrastructure projects, or utility substations.

3. High-Voltage (HV) Switchgear

HV switchgear generally operates at voltages above 36 kV and is used in power plants and transmission substations. Even so, the classification limits can differ depending on standards or regions. It is designed to handle high electrical voltages in large-scale energy systems so that long-distance power distribution can operate safely.

4. Air-Insulated Switchgear (AIS)

As the name suggests, AIS uses air as an insulating medium. Since air has a low electrical insulation capability, a fairly large distance is required between parts with voltage differences to prevent electricity from jumping (flashover). This makes AIS require a relatively larger installation space.

5. Gas-Insulated Switchgear (GIS)

GIS uses SF6 gas, which has good electrical insulation properties, so that the distance between energized parts can be reduced. This makes the size of GIS smaller, making it suitable for limited spaces. GIS systems are also protected from external factors such as dust and humidity.

The Differences Between Switchgear and Switchboard

In an electrical context, there is a term that sounds similar to switchgear: switchboard. Here are the differences between the two:

Aspects	Switchgear	Switchboard
Purposes	Detects electrical faults and protects the electrical system from those faults.	Safely distributes electricity to various circuits.
Voltage Level	Higher than 36,000 V.	Under 1,000 V.
Maintenance Needs	More intensive.	Simpler and less intensive.
Cost	Relatively expensive.	More cost-effective.
Complexity	More complex, as it consists of various components.	Simpler, as it does not always require additional protection features.
Usage	Systems with high power consumption require higher protection levels, such as substations and large-scale facilities.	Systems with simpler voltage levels and distribution needs, such as in homes and offices.

Reliable & Sustainable Power with KCE

Switchgear is a crucial component in maintaining the safety and reliability of an electrical system. Therefore, the process of installation, testing, and maintenance must be conducted by professionals who understand the electrical system needs of every facility.

If your company is looking for a partner that can help fulfill these needs, PT Chandra Daya Investasi Tbk. (CDI Group) through its subsidiary in power solutions, namely PT Krakatau Chandra Energi (KCE), is the ultimate choice.

For electrical needs, there are two KCE business lines that can be utilized, namely power supply and electrical services.

As a power provider, KCE operates a Gas-Steam Power Plant System (PLTGU) and Combined Cycle Power Plant (CCPP) with a capacity of 120 MW. This system consists of 2 Gas Turbine Generators (GTG), 2 Heat Recovery Steam Generators (HRSG), and 1 Steam Turbine Generator (STG).

Meanwhile, the electrical services line serves the following three main segments:

Operation and Maintenance (O&M) of 30 kV, 20 kV, 6 kV, and 0.4 kV switchgear.
Engineering, Procurement, and Construction (EPC) for power systems.
Repair and overhaul services for transformers and electric motors.

Currently, there are 200+ customers from industrial, business, social, and government sectors, as well as 1,500+ household customers who entrust their electrical needs to KCE.

CDI Group and KCE are ready to be #YourGrowthPartner by providing reliable, precise, and sustainable power solutions. Contact us and consult your needs now!

Frequently Asked Questions (FAQ)

Take a look at frequently asked questions about switchgear below:

1. What Is a Wiring Panel?

A wiring panel is the connection of cables on an electrical panel to distribute energy to devices and areas that require it.

2. Why Is an Interlock System Needed on a Switchgear Panel?

An interlock system is needed on a switchgear panel to prevent operational errors that can cause dangerous conditions, equipment damage, or disruptions to the electrical system.