SF₆ - FREE MEDIUM VOLTAGE IN PRACTICE: UNISEC AIR

Proven in real applications

UNISEC & UNISEC AIR

 

UniSec is an indoor air-insulated switchgear for medium voltage secondary distribution up to 24kV. It offers a broad portfolio of functional units and technical features and is suitable for a wide range of applications including industry, renewable energy plants, distribution and transformer substations, data centers, small generation systems, buildings and infrastructure, and smart grids.   

 

UniSec also offers a sulfur hexafluoride (SF6) free variant called UniSec Air. The new switchgear includes the switch disconnector and disconnector GSec Air. This new component has a dedicated vacuum interrupter for breaking capacity as the insulation medium with a global warming potential (GWP) of zero. The switchgear also contains a vacuum circuit breaker and is fully compliant with IEC standards and the EU F-gas regulation (EU) 2024/573.

 

UniSec and UniSec Air provide robust control and protection, metering, monitoring, and diagnostics suitable for various applications.

UniSec

  • Removable and withdrawable SF6 and vacuum circuit breakers
  • Suitable and certified for installation in the most severe conditions like marine, areas with high seismic hazards, and low temperature environments

 

 

 

UniSec Air

  • GSec Air General purpose switch according to IEC 62271-103
  • GSec Air with dry air insulation medium with Global warming potential (GWP) of 0
  • Compact GSec Air with limited volume (<25 liters) 
  • Removable and withdrawable vacuum circuit breakers
  • Modular and flexible design allows for better accessibility to MV cable connection and simplifies installation, use, and maintenance

UniSec, SF6 

Switch disconnector GSec with SF6 gas.

ABB’s complete transition to SF6 -free switchgear will be phased in line with our ambitious sustainability targets, evolving regulatory deadlines, market demand, and production capacity.

UniSec Air, SF6-free 

Switch disconnector and disconnector GSec Air with dry air and dedicated vacuum interrupter for breaking capacity.

 

Product scope

See below a quick comparison of our products:
  UniSec UniSec Air
Max. rated voltage
 up to 24 kV up to 24 kV 
Max. rated continuous current (busbar) up to 1250 A up to 630 A,  up to 1250 A with LSC2B frontal withdrawable circuit breaker panel
Max. rated short-time withstand current up to 25 kA up to 20 kA, up to 25 kA with LSC2B frontal withdrawable circuit breaker panel
Insulation medium Switch disconnector GSec with SF6 gas Switch disconnector  and disconnector GSec Air with dry air
Standards IEC IEC
Other High duty circuit breakers with M2 (10000 operations) mechanical endurance  High duty circuit breakers with M2 (10000 operations) mechanical endurance 
Applications Building and infrastructure, industry and transportation, data centers, distribution and renewables
 Building and infrastructure, industry and transportation, data centers, distribution and renewables

* ABB’s complete transition to SF6 -free switchgear will be phased in line with our ambitious sustainability targets, evolving regulatory deadlines, market demand, and production capacity

CUSTOMER BENEFITS

Flexible and modular design

This flexible design offers ultimate versatility with a wide range of functional units (from circuit breakers to protection relays) suitable for all indoor applications. Its modularity simplifies installation, operation, and maintenance, and full compatibility between UniSec Air and UniSec ensures effortless integration and easy future expansion, supporting a high degree of customization to meet global needs.

Safe and Reliable Operation

The system ensures safe and reliable operation through comprehensive mechanical and electrical interlocks, maximizing operator protection. Safety is further enhanced by internal arc classification and tailored gas exhaust configurations. Dedicated Service Continuity Solutions (LSC2B/LSc2A/LSC2) are available to minimize service interruption and guarantee high availability when needed most.

Smart Monitoring and Maintenance

Equipped with a comprehensive set of monitoring and diagnostic features, the system provides continuous operational insights to optimize switchgear performance. This smart capability supports a proactive, preventive maintenance strategy, significantly reducing unexpected failures, lowering maintenance costs, and extending the equipment's overall lifespan.

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INSIGHTS

Switchgear is designed once, but worked on for decades

In an era of unprecedented grid expansion, the long-term success of electrical infrastructure will increasingly depend on how well equipment design supports the people responsible for keeping networks running.

Is your SF6-free update really an upgrade?

Compliance, while essential, is only the beginning. A new design may satisfy the regulation, but if it makes those fundamentals harder or slower to manage, it will not feel like much of an upgrade.

SF₆ free MV in practice: UniSec Air

Moving away from SF₆ requires medium-voltage technology you can trust. Watch this 45 minute session to see how UniSec Air is already enabling reliable, air insulated medium voltage energy distribution across utilities, industry and infrastructure. Built on real-world experience, the webinar shares delivered projects and installed base insights, practical learnings from real applications and what this means for engineering, operations and asset management.

From Future Proofing to Field Proven

Over the past four years, ABB and Enedis have co-developed a completely SF6-free switchgear system tailored to the French market. The result: a reliable, regulation-ready solution deployed by Enedis — and a long-term partnership built on a shared innovation approach.

UniSec Air MV Switchgear – the power to adapt

UniSec Air is a medium-voltage switchgear designed for secondary distribution up to 24 kV, 630 A, 20 kA. It contains GSec Air, a general purpose three-position switch disconnector or disconnector for frequent switching applications, with dry air as the insulation medium – that has a global warming potential (GWP) of zero and vacuum interrupter for breaking capacity. UniSec Air is fully compliant with IEC standards and the EU F-gas regulation (EU) 2024 / 573.

View All Insights

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EXPLORE DIGITAL TOOLS & PRODUCT CONFIGURATORS

Partner Hub

Learning

A digital platform that provides training materials, tutorials, and courses to help you build expertise in ABB products and solutions. Accessible resources support continuous learning, professional development, staying current with the latest innovations, and advancing your professional skills.

DOCweb

The ABB online tool for designing electrical MV-LV networks faster and smarter, with real-time calculations, intelligent product selection, automated compliance checks, and instant generation of complete technical documentation, all in just a few clicks.

Product configurators

The online tools that make selecting and customizing ABB Medium Voltage products easier, helping you quickly find the best-fit solution for your technical and application needs, while reducing errors and saving time.

The ABB web portal that connects end users, customers, and partners to product information, configuration tools, training, and expert support, all in one place to simplify collaboration and accelerate projects. It provides a complete end-to-end self-service journey, from design to order placement.

 

EXPORE OUR TOOLS

Assignment Application Description
Product information 3D eCatalogue A visual tool that allows you to explore ABB medium-voltage switchgear in immersive 3D, configure solutions visually, and make informed decisions with instant access to technical details and application insights.
Product information Learning A digital platform that provides training materials, tutorials, and courses to help you build expertise in ABB products and solutions. Accessible resources support continuous learning, professional development, staying current with the latest innovations, and advancing your professional skills.
Configure a product MV switchgear configurator The product tool that enables you to create your single-line diagram (SLD), define switchgear configuration details, and instantly access comprehensive technical documentation, making project design and completion faster and more reliable.
Configure a product MV devices configurator The user-friendly online tool for selecting and configuring ABB Medium Voltage devices (circuit breakers, contactors, ...) with ease and accuracy, helping you customize solutions to fit your specific technical needs.
Configure a product Relays Online The digital platform that offers quick access to ABB protection relay tools, product data, technical documentation, and configuration services, streamlining selection, ordering, and support for Medium Voltage solutions.
Design network/BIM DOCweb The ABB online tool for designing electrical MV-LV networks faster and smarter, with real-time calculations, intelligent product selection, automated compliance checks, and instant generation of complete technical documentation, all in just a few clicks.
Design network/BIM BIMagic The design tool that simplifies the creation and management of Building Information Modeling (BIM) objects for ABB medium-voltage switchgear, streamlining project planning, integration, and ensuring compliance with industry standards.
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FREQUENTLY ASKED QUESTIONS

UniSec Air is an indoor, air‑insulated medium‑voltage switchgear for secondary distribution up to 24 kV.

UniSec Air is used in applications such as substations (utility distribution), large buildings (shopping malls, skyscrapers, resorts), infrastructure (ports, airports, highways, stadiums, hospitals, universities), industry (food and beverage, automotive, semiconductors, pharmaceutical), renewable energy plants, colocation and enterprise data centers and smart grids, where modular and flexible medium‑voltage distribution is required. 

UniSec Air includes enhanced user‑experience features, including clearer visual indicators for switch status, improved visibility of earthing contacts and cable connections, easier door handling and simplified front and lateral cable access. These updates support safer operation, easier installation, and more intuitive maintenance while maintaining compatibility with existing UniSec systems.

UniSec Air is the SF₆‑free version of the UniSec switchgear. UniSec Air contains GSec Air, a general-purpose switch disconnector that uses dry air as the insulation medium - with a global warming potential (GWP) of zero - and vacuum interrupter for breaking capacity. GSec Air incapsulate all medium voltage active parts (contacts) thus preventing the external environment from jeopardizing its functionality (free from humidity, dust, pollution). Conventional UniSec uses an SF₆‑insulated switch disconnector. Both systems share the same footprint, modular design and operational concept. 

Yes. UniSec Air complies with IEC standards and the EU F‑gas regulation (EU) 2024/573, which addresses restrictions on the use of SF₆ in medium‑voltage switchgear. Its SF₆‑free design supports regulatory and decarbonization objectives in medium‑voltage networks. Though the new EU Regulation allows GWP=1, UniSec Air outperforms reaching GWP=0 and supporting end users to enhance their sustainability report and scope 1 and 3 emissions.

Yes. UniSec Air is backward compatible with existing UniSec installations. It is designed with the same footprint and operating principles as UniSec, enabling extensions and upgrades of installed switchgear without major layout changes or system redesign.