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The 27.5kV Single Pole Vacuum Circuit Breaker (ZW7 series) is specifically engineered for electrified railway power distribution systems, where reliable switching performance and high fault-interruption capability are critical. It is widely used in traction power networks operating at 27.5kV, offering stable performance under frequent switching and harsh outdoor conditions.
Designed with a vacuum arc extinguishing chamber and compact single-pole structure, the 27.5kV Single Pole Vacuum Circuit Breaker ensures fast interruption of fault currents while minimizing maintenance requirements. Its lightweight design makes it suitable for pole-mounted and substation feeder applications.
Technical Parameters of the ZW7 Single Pole Circuit Breaker
|
Parameter Name |
Numerical Value |
|
Rated Voltage |
27.5KV |
|
Rated Frequency |
50 Hz |
|
Rated Current |
630/1250/1600/2000/2500 A |
|
Rated Short-Circuit Breaking Current |
20/25/31.5 KA |
|
Rated Short-Circuit Making Current (Peak) |
50/63/80 KA |
|
Rated Dynamic Stability Current (Peak) |
50/63/80 KA |
|
Rated Thermal Stability Current (RMS) |
20/25/31.5 KA |
|
Rated Short-Circuit Breaking Current Time |
30 times |
|
Rated Thermal Stability Time |
4 s |
|
Rated Operating Sequence |
CO-0.3S-CO-180s-CO |
|
Mechanical Life |
10000 times |
|
Permissible Contact Wear Thickness |
4 mm |
|
Secondary Circuit 1-Minute Power-Frequency Withstand Voltage |
2 KV |
|
Weight |
500/750 Kg |
ZW7 Single Pole Circuit Breaker Mechanical Parameters
|
Name |
Numerical Value |
|
Clearance between open contacts |
18±1 mm |
|
Contact over-travel |
4 ±1 mm |
|
Interphase center distance |
700±1 .5mm |
|
Bouncing time of closing contact |
≤5ms |
|
Three-phase on-off asynchrony |
≤2ms |
|
Opening time |
≤50ms |
|
Closing time (electric closing) |
≤100ms |
|
Average opening speed |
1.4-1.8m/s |
|
Average closing speed |
0.9-1.1 m/s |
|
Resistance of each phase conductive circuit |
≤50 μΩ |
The ZW7 series 27.5kV Single Pole Vacuum Circuit Breaker adopts a modular structure consisting of a vacuum interrupter, high-strength composite or porcelain insulators, a spring operating mechanism, and integrated current transformers. The compact configuration reduces installation space while maintaining excellent electrical insulation performance.
Its sealed pole design improves resistance to moisture, dust, and pollution, making it suitable for long-term outdoor railway applications with minimal maintenance requirements.
1. Electrified railway traction power supply systems (27.5kV overhead lines);
2. Urban rail transit feeder and sectioning applications;
3. Substations, switching stations, and overhead line protection systems;
4. Railway infrastructure upgrades and oil-free retrofit projects;
Installation of the 27.5kV Single Pole Vacuum Circuit Breaker is typically performed on utility poles or steel towers. Proper grounding and alignment are essential to ensure operational stability.
After installation, functional testing including opening/closing operation and timing verification should be completed before system integration.
Q1: What is the main application of a 27.5kV Single Pole Vacuum Circuit Breaker?
A: It is mainly used in electrified railway power systems for switching and protecting 27.5kV traction feeders and overhead lines.
Q2: Why is vacuum technology used in this circuit breaker?
A: Vacuum interruption provides fast arc extinguishing, high dielectric strength, and long electrical life, making it ideal for frequent operations.
Q3: Can it be used for retrofit projects?
A: Yes, it is widely used in oil-to-vacuum retrofit upgrades due to its compact structure and oil-free design.
Q4: What environments is it suitable for?
A: It is designed for outdoor railway environments, including high humidity, pollution, and wide temperature variations.
Q5: Does it require regular maintenance?
A: Maintenance requirements are minimal due to its sealed vacuum interrupter and durable mechanical structure.
Address
Jinlu Industrial Zone, Beibaixiang Town, Yueqing City, Wenzhou City, Zhejiang Province, China
