| Brand | ROCKWILL |
| Model NO. | Customization 13.8kV 15.5kV 17.5kV 22kV 230kV 245kV 252KV Dead-Tank SF6 Circuit Breaker |
| Rated voltage | 245kV |
| Rated normal current | 2500A |
| Rated frequency | 50/60Hz |
| Rated short circuit breaking current | 25kA |
| Series | RHD |
Product Description
The RHD-252KV Dead-Tank SF6 Circuit Breaker, is a high-reliability high-voltage electrical device tailored for 220kV and above power transmission and transformation systems. As a core product of the RHD series, it inherits the series’ excellent industrial quality and integrates advanced high-voltage technologies. Its primary functions include distributing combined load currents, interrupting fault currents promptly, and realizing effective control, measurement, and protection of transmission lines. With a compact dead-tank structure that encapsulates key components in a metal casing filled with SF6 gas, the breaker ensures stable operation even in harsh environments, making it an ideal choice for upgrading high-voltage power grids.
Key Features
Superior Seismic Resistance：Adopting a low-center-of-gravity design, the breaker can withstand an earthquake intensity of up to 9 degrees, ensuring stable performance in seismic-prone areas' consistent with the RHD series' proven anti-seismic capability.
Excellent Arc-Extinguishing Performance & Long Service Life：Leveraging the high arc-extinguishing efficiency of SF6 gas, the breaker achieves a rated short-circuit breaking current of ≥50kA. It boasts an electrical life of more than 20 operations and a mechanical life of up to 10,000 cycles, significantly reducing equipment replacement and maintenance costs.
Low SF6 Gas Leakage Rate：The hermetic metal tank structure minimizes SF6 gas leakage, with an annual leakage rate of ≤1%--far below industry averages. This design not only avoids safety hazards from gas leakage but also reduces environmental impact.
Modular Design & Flexible Expansion：It supports on-demand configuration of built-in current transformers (CTs), with up to 15 CTs available for measurement or protection purposes. The standardized module interface allows flexible combination to meet diverse substation design and layout requirements, especially suitable for space-constrained scenarios.
Strong Environmental Adaptability：The breaker operates stably in extreme conditions: ambient temperature ranging from -40℃ to +55℃, maximum daily temperature difference of 32K, altitude up to 3,000m, and air pollution level up to Class IV. It also resists wind pressure of 700Pa (equivalent to 34m/s wind speed) and icing thickness of up to 20mm.
Comprehensive Safety Protection：Equipped with anti-misoperation interlocking devices, it effectively prevents accidents caused by incorrect operations. Before delivery, the breaker undergoes lightning impulse tests to eliminate insulation discharge risks from production and assembly, ensuring reliable quality.
Maintenance-Free Operating Mechanism：It adopts a spring-operated mechanism that is oil-free, gas-free, and maintenance-free. This mechanism delivers stable performance, low noise, and high reliability, reducing long-term operational workload.
Compliance with International Standards：The product fully meets the requirements of GB/T 1984 and IEC 62271-100 standards, ensuring compatibility with global high-voltage power grid systems and facilitating international project applications..
Main characteristics
Electrical
Voltage Ratings: 3.6kV, 4.76kV, 7.2kV, 8.25kV, 11kV, 12kV, 13.2kV, 13.8kV, 15kV, 15.5kV, 17.5kV, 22kV, 22.9kV, 24kV, 25.8kV, 27kV, 33kV, 36kV, 38kV, 40.5kV, 44kV, 60kV, 63kV, 66kV, 69kV, 88kV, 115kV, 123kV, 125kV, 126kV, 132kV, 138kV, 145kV, 150kV, 170kV, 184kV, 204kV, 220kV, 225kV, 230kV, 245kV, 275kV, 330kV, 345kV, 400kV, 765kV, 800kV with a rated short-circuit breaking current of 50kA or 63kA, and we offer customization services.
| Item | Unit | Parameters | |||
| Rated maximum voltage | kV | 230kV/245kV/252kV | |||
| Rated maximum current | A | 1600/2500/3150/4000 | |||
| Rated frequency | Hz | 50/60 | |||
| 1min Power frequency withstand voltage | kV | 460 | |||
| Lightning impulse withstand voltage | kV | 1050 | |||
| First open pole factor | 1.5/1.5/1.3 | ||||
| Rated short circuit breaking current | kA | 25/31.5/40/50/63 | |||
| Rated short - circuit duration | s | 4/3 | |||
| Rated out - of - phase breaking current | 10 | ||||
| Rated cable charging current | 10/50/125 | ||||
| Rated peak value withstand current | kA | 80/100/125 | |||
| Rated making current (peak) | kA | 80/100/125 | |||
| Creepage distance | mm/kV | 25 - 31 | |||
| SF6 gas leakage rate (per year) | ≤1% | ||||
| Rated SF6 gas pressure(20℃ gauge pressure) | Mpa | 0.5 | |||
| Alarm/blocking pressure(20℃ gauge pressure) | Mpa | 0.45 | |||
| SF6 annual gas leakage rate | ≤0.5 | ||||
| Gas moisture content | Ppm(v) | ≤150 | |||
| Heater voltage | AC220/DC220 | ||||
| Voltage of control circuit | DC | DC110/DC220/DC230 | |||
| Voltage of energy - store motor | V | DC 220/DC 110/AC 220/DC230 | |||
| Applied standards | GB/T 1984/IEC 62271 - 100 | ||||
Mechanical
| Name | unit | Parameters | |||
| Opening time | ms | 27±3 | |||
| Closing time | ms | 90±9 | |||
| Minute and conjunction time | ms | 300 | |||
| Together--ivide the time | ms | ≤60 | |||
| Simultaneity of opening | ms | ≤3 | |||
| Closing simultaneity | ms | ≤5 | |||
| Moving contact stroke | mm | 150+2-4 | |||
| Contact contact stroke | mm | 27±4 | |||
| Opening speed | m/s | 4.5±0.5 | |||
| Closing speed | m/s | 2.5±0.4 | |||
| Mechanical life | times | 6000 | |||
| Operation sequence | O - 0.3s - CO - 180s - CO | ||||
| Note: The opening and closing speed and time are the characteristic values of the circuitbreaker when it is single divided and closed under rated conditions. The closing speed is theaverage speed of the moving contact from the rigid closing point to 10 ms before closing, andthe opening speed is the average speed of the moving contact within 10 ms from the justequinox to 10 ms after the separation. | |||||
Application Scenarios
Large-Scale Hub Substations：Ideal for 220kV and above key hub substations, it undertakes the core task of controlling and protecting the main power supply circuit, ensuring stable power transmission to urban and industrial areas.
New Energy Bases：Suitable for high-voltage grid-connection systems of wind power and photovoltaic bases. Its excellent fault-interrupting capability and environmental adaptability guarantee reliable integration of renewable energy into the main grid.
Cross-Regional Power Transmission Projects：Used in long-distance cross-regional power transmission lines, it effectively isolates fault points to prevent power outages from spreading, maintaining continuous and stable power supply between regions.
1. Select the circuit breaker corresponding to the voltage level based on the power grid level
The standard voltage (12/24/40.5/72.5/126/170/245/363/420/550/800/1100kV) is matched with the corresponding nominal voltage of the power grid. For example, for a 35kV power grid, a 40.5kV circuit breaker is selected. According to standards such as GB/T 1984/IEC 62271-100, the rated voltage is ensured to be ≥ the maximum operating voltage of the power grid.
2. Applicable scenarios for non-standard customized voltage
Non standard customized voltage (11/22/44/52/132/230/275/300/345/400/380/765kV) is used for special power grids, such as the renovation of old power grids and specific industrial power scenarios. Due to the lack of suitable standard voltage, manufacturers need to customize according to power grid parameters, and after customization, insulation and arc extinguishing performance must be verified.
3. The consequences of selecting the wrong voltage level
Choosing a low voltage level can cause insulation breakdown, leading to SF leakage and equipment damage; Choosing a high voltage level significantly increases costs, increases operational difficulties, and may also result in performance mismatch issues.
The dead tank design of the SF6 Circuit Breaker enhances safety by ensuring that all high-voltage components are housed within a robust, grounded metal enclosure. This design minimizes the risk of accidental electrical faults, as all live parts are completely shielded from external elements. Additionally, this design reduces the possibility of gas leakage, further contributing to safety during operation. Maintenance and inspection can also be performed more safely due to the isolated configuration.
