Structural Features
The LW36-40.5 SF6 circuit breaker has an outdoor porcelain post-type structure, equipped with the CT35 spring operating mechanism. The mechanism is arranged in a “T” configuration with the body, making the entire unit compact, lightweight, simple in structure, with low operating power, and easy installation and commissioning. The mechanical life is 10,000 operations, making it suitable for frequent operations. It adopts a compressed air arc-extinguishing chamber with excellent breaking performance, and its electrical life reaches 20,000 operations.
The sealing performance is reliable, with static seals using “O”-shaped sealing rings and dynamic seals using “V”-shaped sealing rings with spring pressure compensation structures. The secondary wiring board for the current transformers is produced using pressure injection molding, providing strong anti-aging performance and ensuring an annual leakage rate of <0.5%.
The installation frame and support are made from rolled steel plates, using high-strength standard components, ensuring high mechanical reliability. The internal or external current transformers use microcrystalline alloy materials with high magnetic conductivity, and the accuracy class can reach 0.2 or 0.2S. The product can be equipped with 2 to 4 current transformers per phase.
Main Technical Parameters of Circuit Breaker
| No. | Parameter Name | Unit | Parameter Value |
| 1 | Rated voltage | kV | 40.5 |
| 2 | Rated current | A | 1600 / 2000 |
| 3 | Rated insulation level | kV | 95 (Grounded) / 185 (Contact gap) |
| 4 | Rated short-circuit breaking current | kA | 25 / 31.5 |
| 5 | Rated out-of-step breaking current | kA | 7.9 / 10 |
| 6 | Different-phase ground fault breaking current | kA | 27.4 / 34.8 |
| 7 | Rated breaking current of single capacitor bank | A | 400 |
| 8 | Rated operating sequence | – | O—0.3s—CO—180s—CO* |
| 9 | SF6 gas rated pressure (20℃ gauge pressure) | MPa | 0.45 |
| 10 | Opening time (rated voltage) | ms | 30 ≤ t ≤ 40 |
| 11 | Closing time (rated voltage) | ms | 60 ≤ t ≤ 80 |
| 12 | Rated short-circuit making current (peak) | kA | 63 / 80 |
| 13 | Rated short circuit duration | s | 4 |
| 14 | Rated short-time withstand current | kA | 25 / 31.5 |
| 15 | Rated peak withstand current | kA | 63 / 80 |
| 16 | Mechanical life test | Times | 10,000 |
| 17 | Accumulated breaking times (31.5kA/40kA short-circuit) | Times | 20 |
| 18 | Rated current cumulative breaking times | Times | 2000 |
| 19 | SF6 gas annual leakage rate | % | ≤0.5 |
| 20 | SF6 gas trace moisture content | ppm (V/V) | ≤150×10⁻⁶ |
| 21 | External insulation leakage specific distance | mm/kV | ≥25 / ≥31** |
| 22 | Circuit breaker weight | kg | 1000 |
