High Voltage Sf6 Circuit Breaker

Zhejiang Usune Electric Co., Ltd., a professional high-voltage electrical equipment manufacturer in China, has launched the LW36-110 High Voltage Sf6 Circuit Breaker. This product is a three-phase AC 50Hz outdoor high-voltage switchgear suitable for the control and protection of 110kV power transmission and transformation systems. It can also be used as a tie circuit breaker and switching device assembly.

The High Voltage Sf6 Circuit Breaker adopts a unique "thermal expansion + assisted blowing" arc extinguishing principle, equipped with a CTB-1 type spring operating mechanism, conforming to national and international standards, and possessing excellent arc extinguishing performance, high safety, and stable operating characteristics. As a reliable supplier, Usune is committed to providing high-quality, durable high-voltage switchgear. Its LW36-110 SF6 circuit breaker has been widely used in key projects such as power grids and industrial parks, providing reliable power supply for infrastructure construction.

Core Advantages

1. Advanced Arc Extinguishing Technology

Utilizing a unique "thermal expansion + assisted blowing" arc extinguishing principle, it features short arc extinguishing time, long electrical life, and low operating noise, effectively improving power supply stability.

2. High Safety Performance

Using SF6 gas as the insulation and arc extinguishing medium, it boasts excellent insulation and arc extinguishing performance, eliminating the risk of combustion and explosion, making it suitable for densely populated areas.

3. Stable Operating Mechanism

Equipped with a CTB-1 type spring operating mechanism, it features a simple and compact structure, safe and reliable operation, and strong anti-interference capabilities.

4. Compliance with International Standards

Fully compliant with GB1984-2003 "AC High Voltage Circuit Breakers" and IEC62271-100, 2001 "High Voltage Switchgear and Controlgear—Part 100: High Voltage Circuit Breakers," meeting the technical requirements of global power projects.

Applicable Environmental Conditions

The High Voltage Sf6 Circuit Breaker is designed for outdoor use, offering strong environmental adaptability and suitability for various harsh operating conditions:

1. Ambient Temperature: -30℃ ~ +40℃
2. Altitude: ≤3000m
3. Relative Humidity: Daily average ≤95%, Monthly average ≤90% (at 25℃)
4. Wind Pressure ≤700Pa; Icing Thickness ≤10mm
5. Seismic Intensity: Horizontal Acceleration ≤0.3g, Vertical Acceleration ≤0.15g
6. No flammable, explosive, chemically corrosive, or severely vibrating environments

Product Structure and Working Principle

1. Overall Structure

The High Voltage Sf6 Circuit Breaker adopts an integrated self-extinguishing arc-extinguishing structure. Each phase is a single-pillar single-break (POLE). Each circuit breaker consists of three phases, installed on the same frame, and operated by a spring mechanism, with the three phases mechanically linked. The top of the product features an arc-extinguishing chamber porcelain bushing, the middle section contains a support porcelain bushing and frame, and the mechanism box is suspended below the center of the frame, housing a spring-operated mechanism and electrical control components. An SF6 gas density controller is installed on the front of the frame, which is supported at both ends by supports.

2 Key Components and Functions

- Arc Extinguishing Unit: Employs a self-energizing arc-extinguishing structure. When the circuit breaker trips, the high-pressure thermal expansion within the cylinder extinguishes the arc, ensuring rapid and effective extinguishing.
- Support Insulation Device: Supports the arc-extinguishing chamber insulator and provides insulation to ground for energized components; the insulating rod connects the operating arm and the stop rod, ensuring insulation safety.
- Adsorbent: Installed inside the top end cover of the arc-extinguishing chamber, it keeps SF6 gas dry and absorbs decomposition gases produced by arc decomposition. It needs to be replaced during maintenance.
- Leakage Prevention Structure: Utilizes a combination of static sealing (O-ring + sealant) and dynamic sealing (spring compression seal), achieving an annual SF6 gas leakage rate of ≤0.5%. - Spring-operated mechanism: Enables opening, closing, and reclosing operations with fast action speed (closing time ≤145ms, opening time ≤60ms), stable performance, and supports manual and electric energy storage.

3. Working Principle

- Closing position: System current flows through terminals, stationary contact support rod, stationary main contact, moving main contact, cylinder, intermediate contact, and intermediate flange, forming a circuit through the terminals.
- Opening operation: Under the action of the operating mechanism, the operating arm pulls the insulating rod, piston rod, cylinder, moving arc contact, and nozzle downwards; an arc is generated when the moving and stationary contacts separate. After the moving contact system moves to a specific position, the nozzle opens, compressing SF6 gas to blow away the arc, extinguishing the arc when the current crosses zero.
- Closing operation: The operating mechanism drives the moving contact upwards to the closing position, while SF6 gas enters the cylinder, preparing for the next opening.

Key Technical Parameters

The Usune LW36-110 SF6 circuit breaker boasts excellent technical performance, with key parameters meeting the high standards of 110kV power systems, ensuring stable and efficient operation.

Project Reference

Cas-space Rocket Launch Project

Test Report

Practical Application Case

Case Study: 110kV Power Grid Upgrade Project in Northern China

Project Background: A 110kV power grid in Northern China needed to upgrade its aging switchgear to improve power supply stability and security, facing harsh environments such as low winter temperatures (-25℃) and high wind pressure.

Product Application: The project selected 20 Usune LW36-110 SF6 circuit breakers. Their low-temperature adaptability (-30℃~+40℃) and excellent arc-extinguishing performance effectively solved the problem of unstable operation of aging equipment at low temperatures.

Application Results: Since its commissioning in 2022, the equipment has operated stably for four years without arc-extinguishing failure, gas leakage, or other faults. The annual power supply reliability rate has increased by 0.8%, effectively ensuring normal power supply for residents and industrial enterprises in the area.

FAQ

Q1: What is the service life of the Usune LW36-110 High Voltage SF6 Circuit Breaker, and what maintenance is required during operation?

A1: The product has a mechanical life of 6000 cycles, and a continuous operating life of up to 12 years under normal maintenance. Routine maintenance includes weekly visual inspections (insulator integrity, SF6 gas pressure, etc.) and annual maintenance every 3 years (insulator cleaning, main circuit resistance measurement, etc.). A major overhaul is required when maintenance conditions are met (e.g., 12 years of continuous operation, 2000 rated current interruptions, etc.). Manufacturer Usune provides professional maintenance guidance and spare parts supply to ensure long-term stable operation of the equipment.

Q2: What should be done if an SF6 gas leak occurs in the circuit breaker, and are there any safety risks?

A2: This product adopts a double leak-proof structure (static seal + dynamic seal), with an annual leakage rate ≤0.5%, far below the national standard. If a leak is detected, the leak point can be located using an SF6 gas leak detector. After power is cut off, the sealant or O-ring can be replaced. SF6 gas is non-toxic and non-flammable, but excessive leakage can affect the insulation and arc-extinguishing performance of equipment. The product is equipped with an SF6 gas density controller; it alarms when the pressure is below the alarm value (0.45±0.03MPa) and locks operation when the pressure is below the lockout pressure (0.40±0.03MPa), thus avoiding safety risks.

About Usune

Zhejiang Usune Electric Co., Ltd. is a professional manufacturer and supplier of high-voltage electrical equipment in China, specializing in the research, development, production, and sales of high-voltage circuit breakers, switchgear, and other products. The company's factory possesses advanced production equipment and a strict quality control system, ensuring that every product meets national and international standards. Usune adheres to the philosophy of "Quality First, Customer Supreme," providing customers with high-quality products, professional technical support, and comprehensive after-sales service. It has gained widespread recognition from domestic and international customers and is committed to becoming a leading brand in the high-voltage electrical equipment industry, contributing to the development of the global power industry.