When optimizing and modernizing your energy management program, switchgear should be an integral part – the only question is which type is right for your facilities.
The primary purpose of switchgear is to maintain an uninterrupted power supply to healthy system sections in both low and high-voltage power transformers. It contains individual circuits that distribute power downstream to additional electrical distribution equipment.
It automatically switches off malfunctioning equipment downstream created by system faults to prevent the buildup of abnormal currents that may damage the structure or other connected equipment.
Typical high-voltage switchgear comprises many parts, including fuses, switches, relays, isolators, circuit breakers, lightning arrestors, and indicating devices. All these parts can support a complicated network spanning multiple power stations.
How Does a Switchgear Work?
So how does switchgear control, protect, and isolate electrical equipment and circuits? It works by switching electrical currents on and off and isolating circuits to prevent faults and protect equipment and personnel.
When electrical current flows through switchgear, it is controlled by the circuit breakers, disconnect switches, and fuses. When there is an overload or short circuit in the electrical circuit, the circuit breakers trip, interrupting the flow of current and preventing damage to the equipment or personnel.
Types of Switchgear
There are three main switchgear types:
- Low Voltage Switchgear
- Medium Voltage Switchgear
- High Voltage Switchgear
LV – Low Voltage Switchgear
An LV switchgear is a three-phase power distribution unit that can supply electric power at up to 1,000 volts and current up to 6,000 amps. Often used indoors, these are enclosed in a metal case containing copper conductors and a combination of circuit breakers and isolators.
MV – Medium Voltage Switchgear
This type of switchgear is commonly used for distribution systems with voltage above 1 kV up to 36 kV. Depending on the requirement, MV switchgear can come with metal-enclosed indoor or outdoor units. A dedicated MV substation connects to an MV utility distribution network.
HV – High Voltage Switchgear
A switchgear rated above 36kV AC is a high-voltage switchgear. It is generally classified as gas-insulated indoor-type and air-insulated outdoor-type when used in a high-voltage power system.
What Is High-Voltage Switchgear?
A high-voltage switchgear electrical system is more efficient than the typical apparatus. Its efficiency is derived from the high voltage.
The main reason for using a high-voltage switchgear system is enhanced efficiency. When the power is transmitted at a high voltage, the higher voltage results in a lower current required for the same amount of energy to be distributed.
The lower current requires smaller conductors, which are easier to install, less expensive, and more efficient to distribute over longer distances.
Components of Switchgear
LV Switchgear is often used in large facilities as the main incoming distribution if the power requirements exceed 3000A. Located downstream of the main service transformer and typically serving the facility at 480V, this switchgear can include circuit breakers or fuses to protect outgoing circuits.
Digital relays can also be used in this gear for finite control of the protection and allow for the ability to monitor other system conditions beyond overcurrent conditions.
MV Switchgear is located upstream of the transformer, stepping down the requirements to 480V for normal facility use. Typically used in larger facilities where multiple services are incoming from the utility, this switchgear can be looped between one another for redundancy.
HV Switchgear is typically used in utility applications in substations and large campus situations with multiple buildings. HV Switchgear is distributed in a loop system across the campus depending on the use case and then stepped down to MV or LV. In these instances, the circuit breakers would be a vacuum, SF6, etc. breakers or equivalent with relay control or just provided with simple fuse switch protection.
All switchgear has the same common construction a metal frame exterior with copper or aluminum bus bars on the interior that distribute power horizontally across multiple sections, which then connect to vertical bus bars that distribute the individual section protective devices.
Incoming cabling hits the main protective device or stabs off the horizontal bus as the incoming supply. Outgoing cabling will be connected to the individual circuit breaker or fuse circuits to supply loads downstream.
Applications and Future Use
Switchgear was often used only in the MV and HV industries for the past few decades. As power requirements for facilities increased and technology advanced to shrink the footprint of LV Switchgear, it has become more commonly used as a more flexible solution for high-power requirement situations over 3000A to reduce the footprint of gear required.
Besides widespread power station applications, switchgear is used across various commercial and industrial units. For instance, it maintains large motors in a water treatment plant. Construction companies often install switchboards to control power to certain parts of the building site. It is also commonly deployed to serve the hospitality, pharmaceutical, food processing, and consumer goods sectors.
With the rise of electric vehicles and the required charging systems for commercial use and industrial infrastructure for delivery purposes, switchgear for large distribution networks will soon increase the need for both LV and MV.
By 2027, the switchgear market is poised to reach $120.1 billion. The rising cost of electricity, new regulations, and demand for energy-efficient systems drive this demand. As a result, the market is quickly transforming from traditional switchgear systems to digital and intelligent switchgear.
Your organization is likely looking to deploy eco-efficient and high-voltage switchgear systems for smart energy management to save costs. Amid the rising electricity demands, there is little doubt that high-voltage switchgear will play a pivotal role in maximizing efficiency.
Switchgear Solutions to Optimize Assets & Reliability
High-voltage switchgear is essential to any power system’s safe and reliable operation. SEAM Group features a team of longtime leaders in the switchgear sector and has the expertise to provide reliable, efficient, cost-effective solutions for any application.