HV SF6 Dead tank Circuit Breaker supplier 420kV

Attributes Description Documentation Resource Library

Key attributes

Brand	ROCKWILL
Series	RHD
Rated maximum voltage	420 kV
Rated maximum current	3150~5000 A
Lightning impulse withstand voltage	50~63 kA
Rated peak withstand current	125~158 kA

Description

Our 420kV dead tank SF6 high voltage circuit breaker is engineered for EHV power transmission and substation power distribution applications. Equipped with a full pure spring operating mechanism, it eliminates hydraulic and pneumatic auxiliary drives, featuring a streamlined structure and outstanding operational stability. Optimized for harsh outdoor power operation environments, it serves as the core primary equipment for switching on/off and fault interruption in extra-high voltage power grids.

Core Technical Advantages

1. Pure Spring Operating Mechanism, Oil-free & Air-free, Low Maintenance Frequency

Fully fitted with a pure spring-driven operating mechanism without hydraulic or pneumatic auxiliary systems, it reduces the number of components and potential fault points, greatly boosting mechanical reliability.
The mechanism achieves a mechanical endurance rating of ≥10,000 operating cycles, maintaining stable performance under long-term frequent switching operations.
It meets oil-free and air-free operation requirements, eliminating the maintenance procedures of hydraulic oil replacement and air pipeline inspection, and significantly simplifying on-site maintenance work.

2. Self-Energy Self-Blast Arc Extinguishing Principle, Low Operating Power Consumption & Superior Arc Extinguishing Performance

Adopting the self-blast self-energy arc extinguishing principle, it leverages the self-energy of electric arcs to drive SF6 gas flow for arc extinction, drastically cutting the operating power required for closing and opening operations.
It delivers excellent arc interruption capacity with fast short-circuit fault breaking speed, effectively restraining arc ablation and improving equipment safety and service life throughout its full lifecycle.

3. Dual-Seal Flange Structure, Ultra-Low Gas Leakage Rate, Suitable for All-Weather Outdoor Operation

The tank connecting flanges adopt a dedicated double-layer sealing design: the outer sealing ring provides waterproof and dustproof performance, while the inner sealing ring tightly seals SF6 insulating gas to ensure air tightness.
Dual-layer protection drastically reduces the gas leakage rate of the tank. The breaker can withstand harsh outdoor conditions including heavy rain, dust and drastic day-night temperature differences, eliminating frequent gas refilling during long-term outdoor service.

4. Standardized Monitoring and Insulation Configuration

Insulation structure: Single/three-phase post-type porcelain insulator scheme with insulation strength matching the 420kV extra-high voltage level.
Gas monitoring: Standardly equipped with pointer-type density relays to visually and real-time monitor the pressure and density of SF6 gas inside the tank, providing clear early warnings for gas leakage and insufficient pressure.
Standard compliance: The whole product fully complies with multiple global power industry standards including IEC, CEI, GB, JB and DL. It is universally applicable to domestic and overseas substation projects and meets the qualification requirements for both export and domestic power grid bidding.

Main Technical Parameters

Item	Specification
Rated maximum voltage	420 kV
Rated maximum current	3150~5000 A
Rated frequency	50/60 Hz
Lightning impulse withstand voltage	1425/1560 kV
Rated short-circuit breaking current	50~63 kA
Rated peak withstand current	125~158 kA
Creepage distance	25~31 mm/kV
Partial discharge	≤10 pC
Opening time	≤30 ms
Alarm/blocking pressure	0.55/0.50 MPa
Gas moisture content	≤150 ppm(v)
Heater voltage	AC220 V
Voltage of energy-store motor	DC110/220 V
1min Power frequency withstand voltage	630/720 kV
First open pole factor	1.3
Rated short-circuit duration	3 s
Rated cable/line charging breaking current	400~500 A
Rated making current (peak)	125~158 kA
Operation sequence	O-0.3s-CO-180s-CO
Breaking time	≤60 ms
Closing time	≤100 ms
Rated SF₆ gas pressure	0.6~0.7 MPa
SF₆ annual gas leakage rate	≤0.5%
Mechanical life	10000 times
Voltage of control circuit	DC110/220 V
Applied standards	GB/T 1984 / IEC 62271-100

Standard Service Environmental Conditions

Ambient temperature: -40℃ ~ +55℃
Humidity: Daily average relative humidity ≤95%, monthly average ≤90%
Wind pressure: ≤700 Pa
Max. installation altitude for standard model: 3000 m
Earthquake resistance intensity: ≤9 degrees
Air pollution grade: Class Ⅲ

Application Scenarios

The 420kV dead tank SF6 circuit breaker is widely applicable to the following projects:

420kV ultra-high voltage substations
Long-distance transmission line switching stations
Large-scale new energy booster stations
Thermal power plants
Power distribution systems for metallurgical and mining heavy industries
Overseas EPC power engineering projects

Documentation Resource Library Dead Tank Circuit Breakers

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Dead Tank Circuit Breakers Catalog

Catalogue

English

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Public.

RHD-420 SF6 Gas Dead tank Circuit Breaker FLYER

Brochure

English

PDF

Restricted.

RHD-Dead Tank SF6 Circuit Breaker Catalog

Catalogue

English

Consulting

Public.

Rockwill Electric Group Profile

Brochure

English

PDF

FAQ for Dead Tank Circuit Breakers

Q: What are the requirements for monitoring the gas decomposition products of the SF6 tank circuit breaker?

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.

Q: What are the leakage rate requirements for the arc quenching chamber of a tank-type circuit breaker?

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.

Q: What are the characteristics of the interrupter in a tank-type circuit breaker?

The interrupter is typically installed inside the tank, resulting in a highly compact overall structure that enables efficient arc quenching within a limited space. Depending on the arc extinguishing principle and technical approach, the specific configuration of the interrupter may vary, but all designs include core components such as moving/stationary contacts, a nozzle, and insulating parts. During opening operation to interrupt the current, these components work together to achieve fast and reliable extinction of the arc.

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Pricing calculator

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RHD-420 SF6 Gas Dead tank Circuit Breaker FLYER

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Rockwill Electric Group Profile

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Whole life care manager

Whole-life care management services for equipment procurement, use, maintenance, and after-sales, ensuring safe operation of electrical equipment, continuous control, and worry-free electricity consumption.

The equipment supplier has passed platform qualification certification and technical evaluation, ensuring compliance, professionalism, and reliability from the source.