| Brand | ROCKWILL |
| Model NO. | Dead Tank SF6 Circuit Breaker (330kV-420kV) from manufacturer |
| Rated voltage | 420kV |
| Rated normal current | 5000A |
| Rated frequency | 50/60Hz |
| Series | RHD |
In the development history of China's GIS tank circuit breakers, we are undoubtedly the pioneer — as the first source manufacturing enterprise focusing on this field, decades of technological inheritance and continuous innovation have not only laid a solid foundation for mature manufacturing but also kept us at the forefront of Research and Development and innovation. With reliability that exceeds market expectations, our products have become the preferred choice for numerous major power projects.
330kV to 420kV Dead tank SF6 circuit breaker products are composed of inlet and outlet bushings, current transformers, interrupters, frames, operating mechanisms and other componentsIt is used to cut off the rated current, fault current or conversion line to realize the control and protection of the power system, and is widely used in domestic and overseas electric power, metallurgy, mining, transportation and public utilities industries.
High-Efficiency Arc Extinction and Insulation: Utilizes SF6 gas for rapid arc extinction and excellent insulation performance, capable of quickly interrupting fault currents to ensure stable operation of power systems at the 420kV voltage level.
Robust Sealed Structure: Adopts a dead-tank design, sealing live components within a metal tank filled with SF6 gas to isolate them from the external environment. Features outstanding seismic resistance and dust-proof capability, adapting to complex environments.
Integrated Multifunctionality: Integrates components such as bushings and current transformers, combining functions like current measurement and protection control to simplify system configuration and improve operation and maintenance efficiency.
Long Lifespan and Low Maintenance: Exhibits long mechanical and electrical service lives. The sealed structure effectively reduces component aging and corrosion, significantly decreasing maintenance frequency and saving operational costs.
Multiple Safety Protections: Equipped with anti-misoperation interlocking devices and comprehensive insulation protections to effectively prevent human errors and fully safeguard the safety of personnel and equipment during operation.
Among these, some SF6 tank circuit breakers cover non-standard voltage levels including 225kV to 800kV, with a rated short-circuit breaking current of 50kA or 63kA, and offer customization services.
|
Serial number |
project |
parameters |
|
1 |
Rated voltage |
330kV/345kV363kV/380kV/ 400kV/420kV |
|
2 |
Rated Current |
5000A |
|
3 |
Rated frequency |
50/60Hz |
|
4 |
Rated short-circuit breaking current |
63kA |
|
5 |
Rated short-circuit closing current |
171kA |
Integral Tank Structure: The breaker's arc quenching chamber, insulating medium, and related components are sealed within a metal tank filled with an insulating gas (such as sulfur hexafluoride) or insulating oil. This forms a relatively independent and sealed space, effectively preventing external environmental factors from affecting the internal components. This design enhances the insulation performance and reliability of the equipment, making it suitable for various harsh outdoor environments.
Arc Quenching Chamber Layout: The arc quenching chamber is typically installed inside the tank. Its structure is designed to be compact, enabling efficient arc quenching within a limited space. Depending on different arc quenching principles and technologies, the specific construction of the arc quenching chamber may vary, but generally includes key components such as contacts, nozzles, and insulating materials. These components work together to ensure that the arc is quickly and effectively extinguished when the breaker interrupts the current.
Operating Mechanism: Common operating mechanisms include spring-operated mechanisms and hydraulic-operated mechanisms.
Spring-Operated Mechanism: This type of mechanism is simple in structure, highly reliable, and easy to maintain. It drives the opening and closing operations of the breaker through the energy storage and release of springs.
Hydraulic-Operated Mechanism: This mechanism offers advantages such as high output power and smooth operation, making it suitable for high-voltage and high-current class breakers.
The leakage rate of SF₆ gas must be controlled at an extremely low level, typically not exceeding 1% per year. SF₆ gas is a potent greenhouse gas, with a greenhouse effect 23,900 times that of carbon dioxide. If a leak occurs, it can not only cause environmental pollution but also lead to a decrease in the gas pressure within the arc quenching chamber, affecting the performance and reliability of the circuit breaker.
To monitor the leakage of SF₆ gas, gas leakage detection devices are typically installed on tank-type circuit breakers. These devices help to promptly identify any leaks so that appropriate measures can be taken to address the issue.
During the normal operation and interruption processes of a circuit breaker, SF₆ gas can decompose, producing various decomposition products such as SF₄, S₂F₂, SOF₂, HF, and SO₂. These decomposition products are often corrosive, toxic, or irritating, and therefore require monitoring.If the concentration of these decomposition products exceeds certain limits, it may indicate abnormal discharges or other faults within the arc quenching chamber. Timely maintenance and handling are necessary to prevent further damage to the equipment and to safeguard personnel health.
Focus on three core points: First, voltage matching, which must conform to the maximum operating voltage of the system (compatibility coefficient ≤1.05); second, customization of key parameters — the break spacing of 345kV equipment is reduced by 5%-8% compared with 363kV, and the voltage equalizing capacitor of 380kV equipment is increased by 8%-10%; third, the short-circuit breaking current shall be ≥50kA, and the third-party insulation coordination test must be passed.
