SF6 Load Break Switch

SF6 Load Break Switch for Ring Main Units — Compact, Sealed & Low-Maintenance Medium Voltage Solution

Shenzhen Dongshengyuan Electrical Equipment Co., Ltd. (DSY Switchgear), established in 2005 with RMB 50.6 million registered capital, specializes in manufacturing high-performance SF6 Load Break Switch tailored for medium-voltage power distribution networks. This product covers rated voltages of 7.2kV to 24kV, rated current up to 1250A and 4-second short-time withstand current up to 31.5kA. Adopting a fully sealed SF6 gas chamber structure and complying with IEC 62271-103 industry standards, it is widely matched with ring main units and applied in urban residential distribution, industrial power systems and photovoltaic grid connection projects across global markets.

What Is an SF6 Load Break Switch?

An SF6 Load Break Switch is a professional medium-voltage switching device that takes sulfur hexafluoride (SF6) gas as the core medium for insulation and arc extinction. It is mainly used to switch, carry and break normal load current and conventional overload current in medium-voltage distribution systems, serving as a key control and protection component for ring network power supply.

Different from traditional air-insulated switches that are prone to dust pollution, metal oxidation and frequent failure, this product adopts an integral fully sealed SF6 structure. The high-strength stainless steel enclosure isolates internal conductive contacts from external humidity and corrosive substances, realizing compact installation and maintenance-free operation. It is highly compatible with modern ring main units (RMUs) and urban underground power distribution networks.

Featuring a lifelong sealed design, the switch requires no gas refilling throughout its 20–30 year service life, effectively reducing long-term operation and maintenance costs and delivering excellent total cost performance for B-end engineering and procurement projects.

Technical Specifications

Key Product Features

Stable Arc-Extinguishing Performance

SF6 gas boasts excellent electronegativity, which can quickly adsorb free electrons and extinguish electric arcs in a short time during switching operations. This design ensures stable and reliable breaking and closing performance, low operating failure rate and consistent working status throughout the whole equipment lifecycle.

Mechanical Five-Proof Interlock

Each switch is equipped with a standard mechanical five-proof interlock mechanism. The closing, opening and grounding operations are mutually locked logically, which effectively prevents man-made misoperation. It provides dual safety protection for on-site maintenance personnel and supporting power distribution equipment during live working.

Unitized Modular Design

The switch adopts an integrated unitized modular structure. It can be flexibly combined with current-limiting fuses and grounding switches to integrate load switching and short-circuit protection functions in one compact unit, eliminating the need for scattered auxiliary components and simplifying overall cabinet configuration.

Fully Sealed Air Chamber

The fully enclosed SF6 gas chamber is not affected by external temperature changes, humid environment and industrial pollution. It features strong environmental adaptability and can operate stably in coastal humid areas, high-altitude low-pressure environments and industrial sites with corrosive gases.

Intelligent Monitoring Ready

The product reserves intelligent upgrade interfaces and supports optional configuration of professional monitoring sensors. It realizes real-time online monitoring of SF6 gas pressure, internal temperature and switch operating position, enabling seamless docking with SCADA systems and smart grid management platforms to support automated operation.

Applications

Urban Secondary Distribution

Urban power grid construction features dense equipment layout and limited installation space. The compact RMU-matched design saves floor space, while the fully sealed structure effectively avoids internal contamination of underground cable vaults, ensuring stable and continuous urban power distribution.

Renewable Energy Integration

Wind farms and photovoltaic power stations are mostly built in humid, saline-alkali or extreme temperature areas. The SF6 sealed insulation structure resists environmental erosion and performance attenuation, solving the durability problems of traditional air-insulated switches in new energy scenarios.

Industrial and Commercial Power Systems

Large industrial factories and commercial buildings require frequent feeder switching and reliable sectional protection. The optional motorized operating mechanism supports remote control and system docking, fully adapting to automated operation demands of industrial and commercial power distribution systems.

Residential Power Distribution

Residential ring network projects prioritize low maintenance and long-term stability. The lifelong sealed and low-failure design reduces on-site inspection and maintenance frequency, greatly lowering the long-term operational cost of community power supply systems.

Quality Control

DSY Switchgear implements strict full-process quality inspection and performance testing for every SF6 Load Break Switch before delivery to ensure compliance with international standards and project requirements. Core testing items are as follows:

Helium mass spectrometry leak detection — Strictly verifies the airtightness of the SF6 gas chamber, with an annual leakage rate controlled below 0.1% to ensure long-term stable insulation performance.

Mechanical operation tests — Completes 5,000 switching cycle tests to reach M2 mechanical endurance grade, ensuring flexible and stable mechanical operation.

Main circuit resistance measurement — Precisely controls contact resistance within the standard micro-ohm range to avoid equipment overheating during long-term load operation.

Power frequency and lightning impulse withstand tests — Verifies the overall dielectric insulation strength to adapt to various grid voltage fluctuation conditions.

Partial discharge (PD) testing — Eliminates internal insulation defects to prevent long-term insulation breakdown and equipment failure.

Complete type test reports and professional technical drawings are provided for each order to support project approval and procurement filing.

Customization and Supply Capabilities

DSY provides flexible personalized configuration services for B-end engineering customers. We can customize SF6 air chamber parameters, operating mechanisms and contact current specifications according to actual project demands.

We support diversified customized solutions such as OEM brand labeling, motorized actuator installation and intelligent monitoring sensor configuration. Backed by a 40-person professional technical team and more than 60 technical patents, we provide reliable technical support for all customized schemes and deliver full-lifecycle remote after-sales services.

Frequently Asked Questions

Q1: What are the main application scenarios of this SF6 load break switch?

A: It is widely used in urban ring main unit power distribution, residential power supply, industrial and commercial terminal distribution, as well as photovoltaic and wind power grid-connected ring network projects.

Q2: Can this switch independently cut off short-circuit faults?

A: No. It is mainly used for normal load current switching. For short-circuit fault protection, it needs to be used with matching current-limiting fuses or circuit breakers.

Q3: How to monitor the internal SF6 gas pressure status?

A: It can be configured with a temperature-compensated pressure gauge or gas density switch, supporting real-time visual observation and automatic alarm for low gas pressure.

Q4: What is the service life of the equipment?

A: Adopting a lifelong sealed design, it requires no SF6 gas refilling or major maintenance, with a stable service life of 20 to 30 years under normal operating conditions.

Q5: Does SF6 gas cause environmental impact?

A: The fully sealed structure effectively avoids gas leakage during operation. At the end of the equipment life, SF6 gas can be recycled and treated in accordance with IEC 62271-4 standards to meet environmental compliance requirements.

Q6: What technical documents can be provided for project approval?

A: We provide complete supporting documents including type test reports, technical drawings and compliance certificates to support customer procurement review and project filing.

Contact Us

If you are looking for high-quality, low-maintenance and durable SF6 Load Break Switch for your medium-voltage ring network projects, feel free to contact our professional team for accurate product parameters, official quotations and OEM customization services. Email us at [email protected].