High-Stability NU-VZX-12/630-25 VCB for Gas-Insulated Switchgear Systems
Product Description
The NU-VZX-12/630-25 Circuit Breaker is a high-reliability component engineered specifically for 12kV/630A gas-insulated switchgear (GIS) cabinets. This switch utilizes an integrated structure that combines a disconnect switch and a vacuum circuit breaker, streamlining the overall cabinet design while ensuring a short-circuit breaking capacity of 25kA. By employing advanced vacuum arc-extinguishing technology, it provides high safety and stable mechanical performance, meeting the strict requirements of GB/T1984-2017 for modern high-voltage power distribution.
Applications
- Primary protection switch for 12kV gas-insulated switchgear (GIS) in urban and industrial grids.
- Optimized for compact power distribution units requiring integrated isolation and vacuum interruption.
- Suitable for substations requiring stable performance under -40°C to +40°C operating conditions.
Operating Environment Conditions
- Altitude not exceeding 2000 m; seismic intensity not exceeding 8 degrees;
- Pollution degree: II;
- Ambient operating temperature: -40°C to +40°C; relative humidity: daily average not exceeding 90%, monthly average not exceeding 90%;
- Not suitable for installation in locations subject to frequent severe vibrations, or where water vapor, gases, chemically corrosive deposits, salt fog, dust, or dirt significantly affect the performance of the mechanism, or where there is a risk of fire or explosion.
Technical Parameters
Main Technical Parameters
| No. | Item | Unit | Value |
| 1 | Rated voltage | kV | 12 |
| 2 | Rated current | A | 630 |
| 3 | Rated peak withstand current | kA | 63 |
| 4 | Rated short-time withstand current | kA/s | 25/4 |
| 5 | Rated short-circuit breaking current | kA | 25 |
| 6 | Rated short-circuit closing current | kA | 63 |
| 7 | Rated frequency | Hz | 50 |
| 8 | Rated operating sequence | – | 0-0.3s-180s-co |
Mechanical Parameters
| No. | Item | Unit | Value |
| 1 | Circuit breaker main circuit resistance | µΩ | ≤ 30 |
| 2 | Travel | mm | 2-3 |
| 3 | Opening pitch | mm | 8-10 |
| 4 | Bounce | ms | ≤ 2 |
| 5 | Average speed at opening | m/s | 0.6-1.4 |
| 6 | Average closing speed | m/s | 0.4-1.1 |
| 7 | Opening three-phase non-synchronism | ms | ≤ 2 |
| 8 | Closing three-phase non-synchronism | ms | ≤ 2 |
Drawing

FAQ for Gas-Insulated Switchgear Components
- Q: Why is the integrated structure better for GIS cabinets?
A: It reduces the overall footprint and simplifies the linkage mechanism, which is critical for the pressurized and compact environment of a gas-insulated switchgear.
- Q: Does this 12kV VCB require regular maintenance?
A: The vacuum interrupter is maintenance-free for its electrical life, providing a highly reliable solution for sealed GIS environments.
- Q: Can I use this for eco-friendly (SF6-free) gas cabinets?
A: Yes. If you are specifically building a 12kV eco-friendly system, you can also evaluate our NU-GFV-12-630-20 Circuit Breaker.
Inquire Now to receive the NU-VZX-12/630-25 technical catalog or to discuss your GIS project requirements.













