ZN85B-40.5 Indoor High-Voltage Vacuum Circuit Breaker Successfully Developed

ZN85B-40.5 Vacuum Circuit Breaker Successfully Developed

[Baoji, Shaanxi, China, November 27, 2025] Today, Shaanxi West Power Tongzhong Electrical Co., Ltd., a leading domestic manufacturer of smart power transmission and distribution equipment, officially announced that its independently developed next-generation ZN85B-40.5 indoor AC high-voltage vacuum circuit breaker has passed all type tests and successfully rolled off the production line.

The launch of this product marks another significant technological breakthrough in China's 40.5kV indoor switchgear sector, providing more advanced and reliable protection and control solutions for smart grid development, renewable energy integration, and enhanced power quality in industrial applications.

The compact ZN85B-40.5 vacuum circuit breaker is specifically designed for protection and control in 40.5kV power systems. It serves as a core component for power distribution, line protection, and equipment control in substations, industrial and mining enterprises, and large commercial complexes. With a rated current of up to 4000A and a short-circuit breaking capacity of 40kA, all its technical parameters meet internationally advanced standards. Significant Core Technology Advantages Highlight Exceptional Performance Compared to traditional products.

zn85b-40-5-miniaturized-indoor-vacuum-circuit

ZN85B-40.5 demonstrates outstanding innovation and reliability in multiple aspects:

1.Simple and convenient maintenance: The spring mechanism adopts a modular mechanism. The replacement of the closing and opening coil does not require the removal of other components. The user can easily replace it, and no test and adjustment are required after replacement, making the later operation and maintenance more convenient. The life of the permanent magnet mechanism can reach 30,000 times, and it is basically maintenance-free.

2. High conductivity: The optimized insulation cylinder structure and high-performance soft connection sealed pole are adopted to reduce contact resistance and ensure power supply reliability.

3. Wide range of use: Adapt to harsh environments, the product can withstand low temperatures of minus 25℃. Meet the use requirements of 2000 meters above sea level.

4. Economical and affordable: Compared with the high-priced VD4-40.5 series products on the market, our company's ZN85G-40.5 is economical and cost-effective.

The head of the R&D center stated: "The successful development of the ZN85B-40.5 represents years of dedicated effort by our R&D team. We have not only overcome the technical challenge of achieving both miniaturization and high reliability at high voltage levels, but also made forward-looking strategic moves in intelligent capabilities. Moving forward, the company will continue to uphold its philosophy of "Technology Leadership, Customer First," persistently increasing R&D investment to contribute more Chinese wisdom and solutions to global energy transition and smart grid development.

About us

Shaanxi West Power Tongzhong Electrical Co., Ltd. is a high-tech enterprise specializing in the R&D, manufacturing, and sales of power transmission and distribution products. Its comprehensive portfolio includes 7-40.5kV permanent magnet and spring-operated vacuum circuit breakers, contactors, and load switches. These products are widely applied across power, energy, and industrial sectors, with business operations spanning over 20 countries and regions worldwide.