| Brand | ROCKWILL |
| Model NO. | 225kV 220kV 230kV 245kV 252kV Outdoor Dead Tank SF6 Circuit Breaker direct supply |
| Rated voltage | 252kV |
| Rated normal current | 4000A |
| Rated frequency | 50/60Hz |
| Series | LW |
Description
As China's first source factory specializing in GIS tank circuit breakers.225kV, 230kV, 245kV,252kV Outdoor Dead Tank SF6 Circuit Breaker is an outdoor (50Hz) high-voltage power transmission and transformation equipment, which is used to divide and combine rated working current, fault current or conversion lines to achieve protection, control and operation of the power system.
The circuit breaker arc extinguisher adopts the principle of double air chamber and double-action self-energy arc extinguishing, with compact structure, and its technical performance has reached the international level and the domestic advanced level, which is the replacement product of the traditional compressed sulfur hexafluoride circuit breaker. The product is composed of a circuit breaker, a current transformer and an inlet and outlet bushing, and is equipped with a full spring operating mechanism, which can not only carry out split-phase operation, but also realize three-phase electrical linkage.
The product has passed all type tests according to the IEC standards, and has the characteristics of excellent breaking ability, reliable insulation, strong flow capacity, and long electrical and mechanical life.
Main feature
Excellent breaking performance：The self-energy arc extinguishing chamber can meet all terminal short circuits, breaking near area faults, out-of-step faults, out-of-phase grounding faults and line charging currents, etc., with small electrical wear and low arc voltage. The rated short-circuit current can be interrupted 20 times in a row.
Reliable insulation and strong flow capacity：SF6 gas has superior insulation performance and simple and reliable insulation structure. There are few current-carrying contact parts, few contact points, and strong flow capacity.
The structure design is unique：The arc extinguisher has simple structure, few components, light weight, small operating work, high mechanical reliability, and a mechanical life of 10,000 times; The insulation structure of the product has been optimized and designed, which greatly reduces the amount of gas, is conducive to environmental protection, and the structural design is integrated and has strong seismic ability.
Easy to install, maintain and overhaul：The overall commissioning of the factory, rapid on-site assembly, and operation with an integrated spring mechanism, no oil leakage and air leakage, no daily energy storage monitoring requirements, so it is easy to maintain.
Technical specifications
Among these, some SF6 tank circuit breakers cover non-standard voltage levels including 225kV, 230kV, 245kV, 275kV, 330kV, 345kV, 400kV, 756kV, and 800kV, with a rated short-circuit breaking current of 50kA or 63kA, and offer customization services.
Name |
Unit |
Technical Parameters |
|
Rated Voltage |
kV |
252 |
|
Rated Current |
A |
4000 |
|
Rated Frequency |
Hz |
50/60 |
|
First - Pole - To - Clear Factor |
/ |
1.3 |
|
Rated Short - circuit Breaking Current |
kA |
50 |
|
Rated Short - time Withstand Current (Effective Value) |
kA/s |
50/3 |
|
Rated Peak Withstand Current |
kA |
125 |
|
1min Rated Power -frequency Withstand Voltage |
Phase - to - phase/Ground |
kV |
460 |
Break - port |
460(+146) |
||
Rated Lightning ImpulseWithstand (1.2/50μs Peak Value) |
Phase - to - phase/Ground |
1050 |
|
Break - port |
1050(+206) |
||
SF6 Gas (Gauge Pressure, 20 °C |
Rated Gas Pressure |
MPa |
0.60 |
Alarm Gas Pressure |
0.55±0.015 |
||
Lock - out Gas Pressure |
0.50±0.015 |
||
Rated operating sequence |
/ |
O - 0.3s - CO - 180s - CO |
|
Rated out - of - step breaking current |
kA |
12.5 |
|
Short - line - fault breaking current |
kA |
L90:45, L70:35 |
|
Out - of - phase grounding breaking current |
kA |
43.5 |
|
Rated line - charging breaking current |
A |
125 |
|
Number of breaking operations for rated short - circuit breaking current |
times |
20 |
|
Mechanical life |
times |
10000 |
|
Mechanism/operation mode |
/ |
Spring Operating Mechanism/Single - phase Operation |
|
Ambient Temperature：-30℃ ~ +40℃（standard configuration）；optional -40℃ ~ +45℃ for extreme cold/hot regions (with special insulation and heating/cooling design).
Altitude：≤ 1000m above sea level（standard）；for altitudes 1000m~2000m, insulation performance is enhanced by derating to ensure voltage resistance.
Relative Humidity：Monthly average ≤ 90%（at 25℃）；daily average ≤ 95%；no condensation on the tank surface.
Wind Speed：Maximum sustained wind speed ≤ 34m/s（12-level wind）；instantaneous gust ≤ 50m/s.
Atmospheric Conditions：Suitable for areas free of severe dust, corrosive gases（such as sulfur dioxide, ammonia）, flammable gases, and conductive pollutants；for coastal or industrial areas with salt fog, optional anti-corrosion coating and sealed insulation structure are available.
Seismic Resistance：Seismic intensity ≤ 8 degrees；horizontal acceleration ≤ 0.2g, vertical acceleration ≤ 0.1g（conforms to GB/T 13540 or IEC 60068-2-57 standards）.
Rainfall：Maximum rainfall intensity ≤ 100mm/h；no long-term heavy rain erosion on the upper casing.
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.
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.
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.
