A Practical Guide to SF₆-Free Switchgear for Medium-Voltage Applications

SF₆ has been widely used in medium-voltage switchgear for many years because of its excellent insulation and arc-quenching properties. However, its high global warming potential has led to increasing restrictions on the use of SF₆ in new electrical equipment.

As a result, more utilities, industrial companies and renewable energy developers are considering SF₆-Free solutions when planning new medium-voltage distribution systems.

For many projects, the question is no longer simply whether SF₆ can be replaced, but which alternative technology is suitable for the application.

How Does SF₆-Free Switchgear Work?

There are several approaches to replacing SF₆ in medium-voltage switchgear. These include dry air, nitrogen, solid insulation and other alternative technologies.

TAILI Electric's TL-Air-12 series SF₆-Free gas-insulated switchgear uses dry air or nitrogen as the insulating medium and vacuum interrupters for current interruption.

The high-voltage components are installed inside a welded stainless-steel gas tank. This enclosed design helps protect the internal components from dust, moisture and other external conditions while keeping the switchgear compact.

The TL-Air-12 is available with rated currents of 630 A and 1250 A and has passed type tests conducted by authoritative third-party laboratories in China.

Main Features

• SF₆-Free insulation using dry air or nitrogen
• Vacuum interruption
• Welded 304 stainless-steel gas tank
• Compact metal-enclosed construction
• Five-prevention safety interlocking
• Modular configuration
• Top or side busbar expansion

The configuration can be adjusted according to the customer's electrical requirements and installation conditions.

Where Can SF₆-Free Switchgear Be Used?

SF₆-Free switchgear can be applied in many of the same medium-voltage distribution systems where conventional gas-insulated switchgear is used.

Utility Distribution

For feeder switching, sectionalizing and distribution networks where reliable and compact MV equipment is required.

Industrial Facilities

For incoming power, transformer protection and feeder distribution in factories, industrial parks and manufacturing facilities.

Commercial Buildings

For shopping centers, office buildings, infrastructure and other projects where electrical room space is limited.

Renewable Energy Projects

For solar PV plants, wind power projects and other renewable energy applications where reducing the use of fluorinated greenhouse gases is part of the project requirements.

Transformer Substations

SF₆-Free RMUs can be combined with medium-voltage transformers and LV switchgear to form compact distribution substations.

Project Example: SF₆-Free Switchgear for a European Customer

TAILI Electric has supplied SF₆-Free switchgear solutions to overseas customers.

In one European project, the customer was looking for a compact MV switchgear solution with reliable switching performance and an SF₆-Free configuration.

Our engineering team reviewed the project requirements and proposed a solution based on dry-air insulation and vacuum interruption. The electrical parameters, functional units and connection arrangements were discussed with the customer before production.

The final configuration was designed around the customer's distribution system and installation requirements.

This type of project also shows why SF₆-Free switchgear should not be treated simply as a replacement for an existing SF₆ cabinet. The rated voltage, insulation level, short-circuit requirements, cable connection, busbar arrangement and installation conditions all need to be considered when selecting the equipment.

For projects with non-standard requirements, TAILI Electric can review the customer's technical specifications and work with the engineering team to develop the appropriate configuration.

Why Consider SF₆-Free Switchgear?

For new medium-voltage projects, SF₆-Free equipment offers several practical advantages.

First, it eliminates the need to use SF₆, a high-GWP fluorinated greenhouse gas.

Second, technologies such as dry-air insulation and vacuum interruption are already available for medium-voltage distribution applications.

Finally, choosing an SF₆-Free solution can help customers prepare for tighter environmental requirements. In Europe, Regulation (EU) 2024/573 introduces restrictions on the use of fluorinated greenhouse gases in new medium-voltage switchgear.

For customers developing new distribution systems, renewable energy projects or industrial substations, evaluating SF₆-Free equipment at the early design stage can therefore be worthwhile.

FAQ

Q1：Is SF₆-Free switchgear suitable for outdoor or humid environments?

The suitability depends on the specific product design and installation conditions. A sealed gas tank helps isolate the high-voltage components from the external environment, but the complete equipment configuration still needs to be selected according to the site conditions.

Q2：Does SF₆-Free switchgear require gas maintenance?

The gas tank is designed as a sealed system. Under normal conditions, routine gas handling is not required. However, equipment condition and gas pressure should be checked according to the manufacturer's maintenance recommendations.

Q3：Can SF₆-Free switchgear be customized?

Yes. Parameters such as rated current, functional units, cable connections, busbar arrangement and other interface requirements can be discussed according to the project specification.

A Practical Choice for New MV Projects

SF₆-Free technology is becoming an important option for new medium-voltage distribution projects. Dry air or nitrogen insulation combined with vacuum interruption provides a practical way to reduce the use of SF₆ while maintaining the functions required for modern MV distribution.

TAILI Electric's TL-Air-12 SF₆-Free gas-insulated switchgear is designed for utility distribution, industrial facilities, renewable energy projects, commercial buildings and transformer substations.

If you have a project requiring SF₆-Free MV switchgear, TAILI Electric can review your technical specification and recommend a suitable configuration.