Indoor High Voltage Vacuum Circuit Breaker
Indoor High Voltage Vacuum Circuit Breaker for Medium-Voltage Switching — Reliable, Customizable, Maintenance-Free
DSY Switchgear's Indoor High Voltage Vacuum Circuit Breaker is engineered for medium-voltage protection and breaking in industrial, commercial, and infrastructure applications. Rated at 7.2kV to 40.5kV, with rated currents from 630A to 4000A and short-time withstand current up to 50kA/4s, it delivers proven performance across demanding environments. Built on vacuum arc extinguishing technology and a spring operating mechanism, this breaker meets IEC 62271-100 and GB standards. With 60+ patents and qualified supplier status for State Grid and China Southern Power Grid, DSY brings enterprise-grade reliability to every unit.
What Makes This Vacuum Circuit Breaker Different
The vacuum arc extinguishing chamber, a hermetically sealed device that exploits the high dielectric strength of vacuum to extinguish fault current without any arc overflow, is the central component of this product. By quenching the arc at the initial current zero crossing, contact degradation is reduced and electrical life is greatly increased.
This method eliminates the need for hazardous material handling, gas monitoring, and reloading, in contrast to SF6-based breakers. Throughout its service life, the vacuum interrupter ensures constant insulation integrity by keeping vacuum pressure below the crucial 10⁻Pa barrier.
Fast and dependable opening and shutting operations with millisecond precision are made possible by the spring operating mechanism's mechanical energy storage. This design works with both manual and motorized charging options, has been tested in the field, and is simple to maintain.
Technical Specifications
| Parameter | Value |
|---|---|
| Rated Voltage | 7.2kV / 12kV / 24kV / 40.5kV |
| Rated Frequency | 50Hz / 60Hz |
| Rated Current | 630A – 4000A |
| Rated Short-Time Withstand Current | 20 / 25 / 31.5 / 40 / 50kA (4s) |
| Arc Extinguishing Method | Vacuum Arc Extinguishing Chamber |
| Operating Mechanism | Spring Operating Mechanism |
| Structure Type | Handcart Type / Fixed Type |
| Applicable Standards | IEC 62271-100, GB/T 11022, GB 1984 |
| Adaptable Cabinet Types | Incoming line, outgoing line, bus coupler, capacitor |
Key Product Advantages
Long mechanical and electrical life. The vacuum interrupter is rated for 20,000 to 30,000 operations, making it ideal for applications with frequent switching cycles — such as capacitor banks, motor feeders, and tie-breaker positions.
Maintenance-free operation. The vacuum arc extinguishing chamber is a sealed unit requiring zero medium replacement or routine internal inspection. This significantly reduces your total cost of ownership over the breaker's service life.
Complete safety configuration. Each unit is equipped with mechanical interlocking, opening and closing position indication, and a closing locking function. Overcurrent and short-circuit fault breaking protection are built in to ensure safe cabinet operation.
Modular and versatile structure. The standardized modular body adapts to incoming line, outgoing line, bus coupler, and capacitor cabinet configurations. You can deploy the same platform across multiple switchgear types without re-engineering the cabinet layout.
Smart monitoring ready. The breaker supports optional installation of smart sensors for online monitoring of mechanical characteristics, opening and closing coil status, and other key parameters — supporting your transition to intelligent substation management.
Quality Control Process
Every unit goes through a structured five-tier QC inspection before shipment:
Mechanical characteristic testing measures opening and closing speeds, bounce time, and synchronicity to confirm the mechanism operates within millisecond tolerances.
Loop resistance test verifies that primary circuit contact resistance is low enough to prevent localized overheating under continuous load.
Power frequency withstand voltage test checks the dielectric strength of both the vacuum gap and external insulation under rated test voltage conditions.
Vacuum interrupter integrity test uses high-potential (Hi-Pot) testing to confirm the vacuum chamber maintains pressure below 10⁻⁴ Pa — the threshold required for reliable arc extinguishing performance.
Partial discharge measurement ensures that insulating frames and components are free from manufacturing defects that could lead to premature insulation breakdown in service.
A full set of type test reports is provided with every order.
Application Scenarios
This Indoor High Voltage Vacuum Circuit Breaker is widely deployed across multiple B2B sectors where switching reliability is non-negotiable.
Factory power distribution — protects transformer feeders, motor control circuits, and distribution buses against overload and short-circuit faults in manufacturing environments.
Photovoltaic energy storage and renewable energy substations — serves as feeder and tie-breaker in 12kV–40.5kV collection grids, where condensation resistance and high switching frequency are critical requirements.
Data centers — provides fast fault isolation and high operational reliability for uninterrupted power distribution infrastructure.
Municipal indoor switch cabinets and urban infrastructure — compact handcart-type design fits into KYN28 and similar armored metal-enclosed cabinets for metro, rail, and public utility applications.
Heavy industry and metallurgy — the robust mechanism withstands transient recovery voltages and high harmonic distortion typical of electric arc furnace operations.
Customization and Supply Support
DSY supports flexible configuration to match your exact project requirements. Rated current, short-circuit breaking capacity, and operating mechanism type can be adjusted according to your cabinet parameters.
OEM customization is available for panel builders, EPC contractors, and switchgear integrators. Remote technical support, technical drawings, and full-process documentation are provided throughout the project lifecycle.
Frequently Asked Questions
Q1: What arc extinguishing principle does this breaker use?
A: It uses a vacuum arc extinguishing chamber. The vacuum environment provides excellent insulation and quenches the arc at the first current zero — with no arc overflow, no gas emissions, and no contamination risk.
Q2: Which application scenarios is it suitable for?
A: It fits factory power distribution, photovoltaic energy storage, data centers, municipal switch cabinets, heavy industry, and urban infrastructure projects requiring medium-voltage switching from 7.2kV to 40.5kV.
Q3: What safety features are included?
A: Each unit includes mechanical interlocking, position indication, closing locking, and overcurrent/short-circuit fault breaking protection — all standard across the product range.
Q4: How long does the vacuum interrupter last?
A: The mechanical and electrical life exceeds 20,000 to 30,000 operations. The vacuum chamber is hermetically sealed and maintenance-free throughout its service lifecycle.
Q5: Can it adapt to different cabinet types?
A: Yes. The modular body structure is compatible with incoming line, outgoing line, bus coupler, and capacitor cabinet types, and can be customized to match your cabinet parameters.
Q6: Does it require gas refilling like SF6 breakers?
A: No. The vacuum interrupter is a fully sealed ceramic or glass unit — no gas medium is used, no refilling is required, and no SF6 monitoring equipment is needed.
Contact Us
Ready to source a dependable Indoor High Voltage Vacuum Circuit Breaker for your project? Contact DSY at [email protected] for technical support and a customized quote.
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