Overview
The AB-3S-12 series outdoor high-voltage three-phase permanent magnet vacuum circuit breaker is a new generation of pole-mounted intelligent vacuum circuit breaker developed by our company by integrating advanced technologies from home and abroad, drawing on the strengths of various sources, adopting a brand-new design concept, and utilizing high-tech methods. This product can be used as a switch for the 10kV side of the main transformer and the 10kV outgoing line in a 35kV substation, or as a pole-mounted switch in a distribution network. Combined with various control units produced by our company, it can easily realize control, protection, satellite measurement, and communication, making it the preferred equipment for achieving distribution network automation and miniaturization.
Model Meaning

Usage conditions
◆Ambient temperature: not exceeding 40℃; average daily temperature not exceeding 35℃; minimum ambient air temperature -25℃.
◆Relative humidity: daily average not exceeding 95%, monthly average not exceeding 90%; water vapor pressure: daily average not exceeding 2.2 kPa; monthly average not exceeding 1.8 kPa;
◆Altitude: Not exceeding 2000m;
◆The surrounding area is not significantly contaminated by dust, smoke, corrosive and/or flammable gases, vapors, or salt spray.
◆Vibrations or ground movements from outside the switching and control equipment are negligible;
◆The amplitude of induced electromagnetic interference in the secondary system shall not exceed 1.6kV.
Main technical parameters
Main technical parameters of circuit breaker
| Project | Unit | Parameter | |
| Rated voltage | kV | 12 | |
| Rated insulation level | 1-minute power frequency withstand voltage (RMS) | kV | 42 |
| Lightning impulse withstand voltage (peak value) | kV | 75 | |
| Rated frequency | Hz | 50 | |
| Rated current | A | 630/1250 | |
| Rated short-circuit breaking current | kA | 20 | |
| Rated short-circuit making current (peak value) | kA | 50 | |
| Rated operating sequence | Ot1(0.3s)-COt2(3s)-COt2(3s)-CO | ||
| Thermally stable current (4S) | kA | 20 | |
| Dynamically stable current (bee value) | kA | 50 | |
| Rated short-circuit current breaking times | 次 | 30 | |
| CT ratio | 30-1250/1 (5) | ||
| Operating power supply voltage | V | -220(-110) | |
| Creepage distance | ≥ 31 | ||
| Number of machine operations | 次 | 10000 | |
| Weight | kg | 90+40 (quarantine) | |
Main technical parameters
Mechanical characteristics and technical parameters of circuit breaker after assembly and adjustment
| Project | Unit | Parameter |
| Contact gap | mm | 11±1 |
| Contact travel (measures the relative position of the contact spring when it is open or closed) | mm | 3±0.5 |
| Average closing speed | m/s | 0.6±0.2 |
| Average tripping speed (per 10mm) | m/s | 1.0-1.4 |
| Closing time | ms | 30-50 |
| Opening time | ms | 30~70 |
| Contact closing bounce time | ms | ≤2 |
| Asynchronous closing of three-phase contacts | ms | ≤2 |
| Asynchronous tripping of three-phase contacts | ms | ≤2 |
| Resistance of each phase conductive circuit | μΩ | ≤120; with isolation ≤170 |
| Interphase center distance | mm | 280±2 |
External dimensions and installation dimensions (mm)