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What is Medium Voltage Switchgear/MV Switchgear?

Comprehensive Guide to Electrical Switchgear: Types, Components, and Applications

Switchgear is a fundamental component of electrical power systems, responsible for controlling, protecting, and isolating electrical equipment. By ensuring the safe operation of power transformers and circuits, switchgear plays a crucial role in maintaining stable voltage levels and preventing system failures.

What is Switchgear?

Electrical switchgear is a system that consists of various switching and protective devices designed to regulate the flow of electricity and safeguard power equipment. It is commonly used in both high-voltage and low-voltage applications. The primary function of switchgear is to protect circuits from faults and interruptions by isolating malfunctioning sections and ensuring the continuous operation of the remaining system.

Key Components of Electrical Switchgear

To construct a reliable switchgear system, various insulating and protective elements are used, including:

  • Standoff Insulators
  • Molded Parts & Arc Chutes
  • Baffle & Bushing Insulation
  • Fuse Tubes & Lead Insulation
  • Bus Bar Insulation & Support
  • Insulating Angles, Channels & Washers
  • Terminal Boards & Fuse Boards
  • Interphase Insulation & Control Rods
  • Gaskets & Spread Bars

These components work together to enhance the durability and efficiency of switchgear systems, ensuring their proper operation under various conditions.

Essential Features of Electrical Switchgear

  1. Fault Isolation – Detects and disconnects faulty circuits to prevent further damage.
  2. Rapid Response – Reacts immediately to electrical faults, minimizing disruptions.
  3. Manual Operation – Provides an alternative control mechanism in case of automated system failure.
  4. Selective Circuit Management – Separates functioning sections from faulty ones to maintain system stability.

Given its significance in power transmission and distribution, choosing a high-quality switchgear manufacturer is essential for ensuring long-term system reliability.

Medium-voltage-switchgear 

What is Medium Voltage Switchgear?

Definition & Features

Medium voltage (MV) switchgear operates at voltage levels between 3 kV and 36 kV, making it suitable for various industrial and commercial applications. It serves a vital role in protecting power distribution networks from short circuits and overloads.

Key functions of MV switchgear include:

  • On/Off Switching Operations – Ensures smooth switching of electrical circuits under normal conditions.
  • Short Circuit Protection – Detects faults and isolates defective components to prevent damage.
  • Capacitive Current Switching – Manages charging and discharging currents of capacitors.
  • Inductive Load Switching – Controls the flow of current in inductive loads.

MV switchgear typically employs SF6 gas, oil, or vacuum as an insulating medium to prevent electrical faults and maintain system stability.

Pole-mounted-substation

Types of Medium Voltage Switchgear

MV switchgear can be categorized into two main types: indoor switchgear and outdoor switchgear.

1. SF6 Gas-Insulated Switchgear (GIS)

  • Compact design with high voltage components enclosed in SF6 gas.
  • Ideal for confined spaces and power transmission networks.
  • Used in renewable energy integration and railway systems.

2. Metal-Enclosed Switchgear

  • Fully enclosed in metal, with minimal ventilation.
  • Designed for indoor applications, providing enhanced safety.

3. Metal-Clad Switchgear

  • A specialized type of metal-enclosed switchgear with additional compartmentalization.
  • Offers higher reliability and ease of maintenance.

4. Air-Insulated Switchgear (AIS)

  • Uses air as the insulating medium.
  • Operates within 11 kV to 36 kV voltage range.
  • Commonly used in medium voltage power systems.

5. Pad-Mounted Switchgear

  • Designed for underground and distribution applications.
  • Used in areas where above-ground space is limited.

6. Vault/Subsurface Switchgear

  • Installed underground to ensure reliable power distribution.
  • Works with voltage levels between 15 kV and 38 kV.

Key Components of Switchgear

Switchgear consists of two primary component categories:

1. Power Conducting Components

  • Circuit Breakers & Fuses – Interrupt excessive current to protect the system.
  • Switches & Isolators – Control electrical connections manually or automatically.
  • Lightning Arrestors – Protect against voltage surges.

2. Control & Protective Components

  • Relays – Detect and respond to system faults.
  • Current & Potential Transformers – Monitor voltage and current levels.
  • Control Panels – Provide centralized monitoring and management.

During normal operation, switchgear ensures seamless power distribution by switching on/off generators, transmission lines, and distribution circuits. In the event of a fault, it isolates the affected section to prevent system-wide failures.

How Does Switchgear Work?

The working principle of switchgear revolves around fault detection, protection, and circuit control. When an electrical fault (e.g., short circuit or overload) occurs, excessive current flows through the system, potentially damaging equipment.

Switchgear components, such as relays, circuit breakers, and fuses, work together to detect these anomalies and automatically disconnect the faulty section, preventing system-wide disruptions.

Core Functions of Electrical Switchgear

  1. Fault Protection – Shields equipment from short circuits and power surges.
  2. Power Isolation – Allows for safe maintenance by disconnecting specific sections.
  3. System Reliability – Enhances power availability by ensuring uninterrupted operation.
  4. Operator Safety – Prevents electrical hazards during system failures.

Advantages of Electrical Switchgear

Switchgear, particularly indoor switchgear, offers numerous benefits:

✅ Enhanced Safety – Enclosed systems reduce the risk of electrical hazards.
✅ Compact Design – Requires minimal space, making it suitable for urban environments.
✅ Increased Durability – Protected from environmental factors, ensuring a longer lifespan.
✅ Lower Operating Costs – Efficient energy management reduces maintenance expenses.
✅ Minimal Electrocution Risk – Grounded metal enclosures provide additional safety.
✅ Reliable Performance – Works effectively under varying load conditions.

Applications of Electrical Switchgear

1. Arc Furnace Operations

  • Arc furnaces require frequent switching, making vacuum circuit breakers in MV switchgear the best option for handling the high electrical demand.

2. Railway Traction Systems

  • Railway systems experience frequent short circuits, requiring circuit breakers with fast response times and high durability.
  • Vacuum circuit breakers are preferred for railway traction due to their rapid fault-clearing capabilities.

3. Industrial Power Distribution

  • Used in factories, refineries, and manufacturing plants to manage electrical loads efficiently.

4. Renewable Energy Integration

  • Essential for solar and wind power stations to regulate electricity flow and prevent system overloads.

5. Utility & Grid Substations

  • Employed in power transmission networks to ensure stable voltage levels.

Conclusion

Switchgear is an essential component of modern electrical infrastructure, ensuring the safe, efficient, and reliable operation of power systems. Whether for industrial, commercial, or utility applications, understanding its types, components, and functions is key to selecting the right switchgear solutions.

By choosing high-quality manufacturers and advanced switchgear technologies, industries can enhance power system performance, reduce operational risks, and improve overall energy efficiency.

Professiona Switchgear supplier and manufacturer 

  1. Zhejiang GONGSHUN Electrical Co.,Ltd (electricgs.com), Our company was founded in the late 1990s, specializing in the production of inflatable cabinets, SF6 inflatable cabinets, and various high and low voltage complete sets of electrical equipment. It has multiple subsidiaries under its jurisdiction, including high-voltage load switch branch, high-voltage circuit breaker branch, high-voltage fuse branch, and technology development branch.Our technical expertise, comprehensive product portfolio and long-term rich experience are helping many customers in need to solve their power problems. We’re happy to help at any time.  Whether you need application product advice or technical assistance, our global service team is committed to providing you with the right support. For more technical information about medium voltage earthing switch, feel free to contact us, send an email to gongshun@electric-cn.com 
  2. Our company specializes in producing 12KV-40.5KV series high-voltage electrical products: FZN58, FLN48, FLN36, FZRN25, FZN21, FN18, ZFN16, FN12, FN8, FN7, FN5, XRNT, XRNP, VS1, ZN28, ZW8, ZW32, JN15, GN19, GN22, GN24, GN30, CLXGN15-12, HXGN □ -12, DXG-12 (L), DFW □ -12 high-voltage cable branch box, CLXGN □ -12 (SF6) series inflatable cabinet 12KV and 35KV cable accessories, etc; CLVXP-12 indoor AC high voltage fixed switchgear, CL-SIS-12 compact solid insulated ring main unit, professional assembly Schneider SC6 (SF6) series load switchgear, ABB produced SFG (SF6) series load switchgear and other series products; Distribution and agency of high-voltage load switches and inflatable cabinets produced by Schneider Electric and ABB; Siemens produces the 3AJ1 series of indoor medium voltage vacuum circuit breakers and other related products. The company has a complete range of products and has been operating safely on domestic and international power grids for a long time, receiving unanimous praise from both new and old users. Among them, multiple products such as FZRN25, FN12, FLN36-12, XRNT-12 have been exported to various countries and regions in East Asia, South Asia, Southeast Asia, Africa, and the United States.