Dongfa Intelligent supplies global C-GIS (Cubicle Gas-Insulated Switchgear) builders with factory-direct 24kV 630A SF6 Gas-Insulated Vacuum Circuit Breakers. The product (Model DF VCB-24) serves as the core protection component in gas-insulated panels, featuring 25kA/31.5kA short-circuit breaking capacity and meeting stringent C2 class capacitor bank breaking requirements. It utilizes a compact 230mm phase spacing design and a modular spring operating mechanism (M2/E2 class), with AC/DC compatible operating voltages. Buyers seeking precise short-circuit fault clearance in sealed, compact gas chamber environments can request a quote for technical selection support.
In previous pages, we introduced the DS (Disconnector) for isolation and the LBS (Load Break Switch) for load control. However, when a short-circuit fault occurs downstream of the gas-insulated panel, only the Vacuum Circuit Breaker (VCB) can rely on its powerful vacuum arc-extinguishing capability to cut off fault currents as high as 25kA or even 31.5kA within milliseconds. This DF VCB-24 uses a solid-sealed pole structure combined with the composite insulation of the SF6 gas chamber, making it the most critical "main safety switch" in the entire C-GIS system.
C-GIS cabinet space is extremely limited, and this breaker's phase spacing is compressed to 230mm. However, the drawing parameters show it still achieves 125kV (phase-to-phase/earth) / 145kV (interrupter gap) lightning impulse withstand. This is due to the dual insulation of the extremely high vacuum inside the interrupter and the external SF6 gas. Squeezing massive short-circuit breaking capacity into a small space without sacrificing insulation margin is the biggest engineering highlight of the DF VCB-24.
The drawing shows this model not only offers 630A/1250A current options but supports up to 31.5kA (peak 80kA) short-circuit breaking. Combined with M2 class mechanical life (against mechanical wear) and E2 class electrical life (against arc erosion), it can handle highly frequent protection actions, such as frequent fault clearance on renewable energy collector lines.
In modern distribution networks, reactive power compensation capacitor banks, long cable lines, and renewable inverters generate a large amount of capacitive loads. When breaking capacitor banks, restrikes and extremely high switching overvoltages easily occur, damaging equipment insulation. The DF VCB-24 parameter table explicitly marks its capacitor bank breaking class as C2, meaning it has passed strict back-to-back capacitor bank breaking tests. It can effortlessly handle harsh capacitive load switching, effectively suppressing switching overvoltages and protecting other electronic components inside the cabinet.
The drawing shows the breaker uses a modular spring energy storage mechanism, supporting AC110V/220V, DC110V/220V operating voltages. More notably, its wide operating voltage range (e.g., extremely wide ranges from 40.8V to 8V for DC) ensures that the breaker can still reliably charge and close/open even when the control power voltage fluctuates or power capacity is weak in remote mountain substations.
| Parameter | Specification |
| Model | DF VCB-24 |
| Rated Voltage (Ur) | 24 kV |
| Rated Frequency (fr) | 50 Hz |
| Rated Current (Ir) | 630 A / 1250 A |
| Rated Short-Circuit Breaking Current | 25 kA / 31.5 kA |
| Rated Short-Time Withstand Current (Ik) | 25 kA / 31.5 kA (4s) |
| Rated Short-Circuit Making Current (Peak) | 63 kA / 80 kA |
| Capacitor Bank Breaking Class | C2 Class |
| Rated Lightning Impulse Withstand (Phase/Earth / Gap) | 125 kV / 145 kV |
| Rated Short-Duration PF Withstand (Phase/Earth / Gap) | 65 kV / 60 kV |
| Mechanical / Electrical Endurance | M2 / E2 |
| Rated Operating Sequence | O-0.3s-CO-180s-CO |
| Operating Voltage | AC/DC 110V, 220V |
| Phase-to-Phase Distance | 230 mm (Standard, customizable matrix) |
The bottom of the drawing provides three phase spacing combinations for builders to choose based on panel width:
Achieves 31.5kA short-circuit breaking at 230mm phase spacing, perfectly matching the compact and highly reliable design concept of C-GIS.
Passes strict C2 class capacitive load breaking tests, effectively suppressing restrikes and switching overvoltages to protect cabinet insulation safety.
High mechanical and electrical endurance reduces maintenance needs, matching the 20+ year lifecycle of C-GIS equipment.
Supports AC/DC 110V/220V and reliably operates within an extremely wide voltage fluctuation range.
Dongfa Intelligent factory-direct supply. Can be purchased together with DS and LBS for uniform dimensional matching inside the gas chamber.
Dongfa Intelligent (Zhejiang Dongfa Intelligent Electric Technology Co., Ltd.) was founded in 2012, with 14 years of focus on high-voltage electrical manufacturing. VCB is the component with the highest technical barrier. We have Automatic Pressure Gelation (APG) production lines to ensure solid-sealed poles are free of bubbles and cracks. Every DF VCB-24 shipped undergoes main circuit resistance testing, mechanical operation testing, dielectric withstand testing, and vacuum degree inspection, ensuring it can be put into reliable operation immediately after SF6 gas filling.
A: A disconnector (DS) in the system only carries the normal short-circuit current (waiting for the upstream breaker to trip), so it only needs to meet thermal stability requirements (e.g., 20kA/1s). A Vacuum Circuit Breaker (VCB) is the execution component that actively cuts off short-circuit faults. It must be able to "forcibly extinguish" arcs as high as 25kA or 31.5kA, which requires extremely high technical specifications.
A: Capacitor breaking is one of the most difficult tasks for a breaker. C2 is a very high class in the IEC standard for capacitor breaking, meaning the breaker can safely cut off capacitor banks (such as back-to-back capacitor banks) without restrikes, preventing dangerous overvoltages.
A: This depends on your switchgear width design. Please refer to the table below the drawing: 210mm suits compact panels, 275mm suits panels with higher insulation distance requirements. Our technical team can assist in confirming the busbar interface.
A: Dongfa Intelligent is an own factory in Yueqing, Zhejiang. Factory audits are supported. You are welcome to visit our solid-sealed pole production line and breaker test benches.
A: Standard products support 1-unit trial orders. Standard lead time is 7–15 working days; custom products take 15–30 working days.
Please provide: System Voltage + Short-Circuit Breaking Requirements + Operating Voltage + Panel Phase Spacing + Quantity.
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No. 281, Wei 18th Road, Yueqing Economic Development Zone, Yueqing, Wenzhou, Zhejiang, China
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