Product Introduction
The LN2-40.5 indoor SF6 circuit breaker is an indoor device designed for use in 50 Hz three-phase AC systems. It is suitable for industrial enterprises, power plants, and substations for protection and control purposes and can be used in locations requiring frequent operations. It can also be used as a link circuit breaker and for switching capacitor banks.
The LN2-40.5 model is equipped with the CT10-A spring operating mechanism but can also be paired with the CD101G electromagnetic operating mechanism.
Main Technical Parameters of Circuit Breaker
(Model: LN2-40.5/1250A-25)
| No. | Parameter Name | Unit | Parameter Value |
| 1 | Rated voltage | kV | 40.5 |
| 2 | Maximum working voltage | kV | 40.5 |
| 3 | Rated insulation level | kV | 185 (lightning impulse, full wave) / 95 (power frequency, 1 min) |
| 4 | Rated frequency | Hz | 50 |
| 5 | Rated current | A | 1250 |
| 6 | Rated short-circuit breaking current | kA | 25 |
| 7 | Rated operating sequence | – | O—0.35s—CO—180s—CO* |
| 8 | Rated short-circuit making current (peak) | kA | 63 |
| 9 | Rated dynamic stability current (peak) | kA | 63 |
| 10 | Rated thermal stability current | kA | 25 |
| 11 | Rated thermal stability duration | s | 4 |
| 12 | Switching current for a single capacitor bank | A | 400 |
| 13 | Rated out-of-step breaking current | kA | 6.3 |
| 14 | Accumulated breaking times (rated current) | Times | 2000 |
| 15 | Accumulated breaking times (rated short-circuit) | Times | 16 |
| 16 | Mechanical life | ||
| – With CT10-A spring mechanism | Times | 6000 | |
| – With CD10IIG electromagnetic mechanism | Times | 5000 | |
| 17 | Closing time | ||
| – Spring mechanism | s | ≤0.15 | |
| – Electromagnetic mechanism | s | ≤0.2 | |
| 18 | Inherent opening time (rated voltage) | ||
| – Minimum operating voltage | s | ≤0.10 | |
| – Maximum operating voltage | s | ≤0.07 | |
| 19 | SF6 gas rated pressure (20℃ gauge) | MPa | 0.65 |
| 20 | SF6 gas alarm pressure (20℃ gauge) | MPa | 0.42 |
| 21 | SF6 gas lock pressure (20℃ gauge) | MPa | 0.4 |
| 22 | SF6 gas annual leakage rate | %/Year | ≤1 |
| 23 | SF6 gas moisture content | ppm (V/V) | ≤150 |
| 24 | Rated operating voltage (CT10-A spring mechanism) | ||
| – Closing coil | V (DC) | 48, 110, 220 | |
| – Opening coil | V (DC) | 48, 110, 220 | |
| – Motor | V (DC) | 110, 220 | |
| 25 | Rated operating voltage (CD10IIG electromagnetic mechanism) | ||
| – Closing coil | V (DC) | 110, 220 | |
| – Opening coil | V (DC) | 48, 110, 220 | |
| 26 | Weight | ||
| – Circuit breaker body | kg | 135 | |
| – SF6 gas | kg | 1.5 |
