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A High Voltage SF6 Circuit Breaker is a high-performance switching device designed for protecting and controlling transmission and substation power systems from medium-high voltage levels up to 145kV. By using sulfur hexafluoride (SF6) gas as both insulation medium and arc extinguishing technology, it provides fast fault interruption, excellent dielectric strength, and long operational reliability for critical electrical networks.
Compared with conventional switching technologies, SF6 circuit breakers offer superior insulation performance and compact construction, making them widely used in high voltage substations, GIS systems, transmission lines, and industrial power networks. Our product range includes different configurations such as indoor GIS applications, outdoor installations, live-tank designs, and dead-tank structures to meet diverse engineering requirements.
The product family includes: 66KV SF6 Circuit Breaker, 66KV Gas Insulated Circuit Breaker, 66KV Outdoor SF6 Circuit Breaker, and Tank Type SF6 Breaker, covering various substation layouts and voltage requirements.
SF6 gas has excellent dielectric recovery capability and arc extinguishing performance, allowing circuit breakers to safely interrupt high short-circuit currents while maintaining compact dimensions. This makes SF6 technology especially suitable for transmission-level applications where reliability, space efficiency, and operational safety are critical.
The breaker adopts a sealed SF6 gas chamber combined with high-performance interrupter technology and precision operating mechanisms. The pressurized gas system provides efficient arc cooling during fault interruption, while temperature-compensated density monitoring ensures reliable insulation performance throughout the service life.
Spring-operated, hydraulic, and spring-hydraulic mechanisms are available according to application requirements. Each mechanism is optimized for consistent closing and opening speed, supporting reliable operation under demanding transmission conditions.
Integrated current transformer options, intelligent monitoring interfaces, and digital communication capabilities allow seamless connection with modern protection relays, SCADA systems, and digital substations.
| Parameter | 66kV Class | 126kV Class | 145kV Class |
|---|---|---|---|
| Rated Voltage | 72.5kV | 126kV | 145kV |
| Rated Frequency | 50Hz / 60Hz | ||
| Rated Current | 1250A / 2000A / 3150A | 2000A / 3150A | 2000A / 3150A |
| Short Circuit Breaking Current | 31.5kA / 40kA | 31.5kA / 40kA / 50kA | 40kA / 50kA |
| Power Frequency Withstand Voltage | 140kV | 230kV | 275kV |
| Lightning Impulse Withstand Voltage (BIL) | 325kV | 550kV | 650kV |
| SF6 Filling Pressure (20°C) | 0.45–0.65MPa | 0.45–0.65MPa | 0.45–0.65MPa |
| SF6 Gas Quality | High purity SF6, dew point ≤ -50°C | ||
| Operating Mechanism | Spring / Hydraulic / Spring-Hydraulic mechanism | ||
| Mechanical Endurance | Class M2, ≥10,000 CO operations | ||
| Electrical Endurance | Class E2 for extended switching duty | ||
| Ambient Temperature | -40°C to +55°C | ||
| Applicable Standards | IEC 62271-100, IEEE C37.04/C37.09, GB 1984 | ||
High voltage SF6 circuit breakers are widely applied in power systems where reliable interruption capability and long-term stability are required.
As an experienced high voltage switchgear manufacturer, we provide customized SF6 circuit breaker solutions for global utilities, EPC contractors, and power equipment distributors.
Each breaker undergoes comprehensive factory testing including insulation withstand tests, partial discharge measurement, gas leakage inspection, timing verification, and mechanical endurance testing before delivery.
Customization options include voltage level selection, current rating, CT configuration, control voltage, communication functions, installation structure, and substation integration requirements.
Q1: What is a High Voltage SF6 Circuit Breaker?
It is a high voltage switching device that uses SF6 gas for insulation and arc extinguishing, allowing reliable interruption of fault currents in transmission and substation systems.
Q2: Why are SF6 breakers used in high voltage substations?
Because SF6 provides excellent insulation strength, fast arc extinction, compact design, and proven reliability for high voltage applications.
Q3: Can SF6 circuit breakers be customized for different grid projects?
Yes. Voltage level, current capacity, installation type, CT configuration, control system, and monitoring functions can be customized according to project requirements.
