Overview
The ZW8-12(G) series vacuum circuit breakers are high-voltage outdoor switchgear with a rated voltage of 12 kV and a three-phase AC 50 H2 rating. They are primarily used for interrupting and closing load currents, overload currents, and short-circuit currents in rural power grids, urban power grids, and small power systems. This product features a three-phase, shared-chamber design with vacuum interrupters housed within a metal enclosure. SMC insulation is used for phase-to-phase and ground insulation, ensuring reliable performance and high dielectric strength. The ZW8-12G combines a ZW8-12 circuit breaker with a disconnect switch, known as a combination circuit breaker. This series utilizes a CT23 spring-energy storage operating mechanism, available in both electric and manual versions. The circuit breaker features closing inrush current control, meeting control and measurement requirements.
Equipped with electronic control unit, it can realize "four remote" monitoring.
Model meaning

Main technical parameters
| Project | Unit | ZW8-12(G)/630-6.3kA | ZW8-12(G)/630-12.5KA | ZW8-12(G)/630-20kA | |
| Rated voltage | kV | 12 | |||
| Rated current | A | 630 | |||
| Rated short-circuit breaking current | kA | 6.3 | 12.5 | 20 | |
| Rated short-circuit making current (peak value) | kA | 16 | 31.5 | 50 | |
| Rated peak withstand current | kA | 16 | 31.5 | 50 | |
| Rated short-time withstand current | kA | 6.3 | 12.5 | 20 | |
| Rated insulation level | Lightning impulse withstand voltage (peak) | kV | 75 | ||
| Rated insulation level | 1min power frequency withstand voltage | kV | 42 | ||
| Rated operating sequence | 分-0.3s-合分-180s-合分 | ||||
| Mechanical life | 次 | 10000 | |||
| Rated short-circuit breaking current breaking times | 次 | 30 | |||
| Rated closing voltage of operating mechanism | V | 110,220 | |||
| Rated opening voltage of operating mechanism | V | 110,220 | |||
| Contact opening distance | mm | 11±1 | |||
| Overtravel (contact spring compression length) | mm | 3±0.3 | |||
| Three-phase opening and closing at different times | ms | ≤2 | |||
| Contact closing bounce time | ms | ≤2 | |||
| Average opening speed | m/s | 1.0±0.2 | |||
| Average closing speed | m/s | 0.7±0.15 | |||
| Opening time | At maximum operating voltage | ms | 15-50 | ||
| Opening time | At minimum operating voltage | ms | 30-60 | ||
| Closing time | ms | 25-50 | |||
| Main circuit resistance of each phase | mo | ≤120(带G≤200) | |||
| Allowable cumulative wear thickness of moving and static contacts | mm | 3 | |||
| weight | kg | 152(带G180) | |||
| Phase center distance | mm | 175±1.5 | |||
Appearance and installation dimensions (mm)
