Product Introduction
The LW36-72.5 porcelain post-type high-voltage AC SF6 circuit breaker is equipped with a CT20 spring operating mechanism. It adopts the self-energy arc extinction principle and features a single-break structure. The three poles of each circuit breaker are mounted on a single frame and are mechanically interconnected through a drive mechanism. The electrical control allows for both remote and local operation.
Main Technical Parameters of Circuit Breakers
| Parameter Name | Unit | LW36-72.5 | LW25-126/145 | LW25-252 | LW15B-252 LW15-252 |
| Rated voltage | kV | 66 | 126 / 145 | 252 | 252 |
| Rated frequency | Hz | 50 | 50 | 50 | 50 |
| Rated current | A | 1250, 3150, 4000 | 2000, 3150 | 4000 | 3150, 4000 |
| Rated breaking current | kA | 25, 31.5 | 40 / 31.5 | 40 | 50 |
| Rated closing current (peak) | kA | 80 | 100 / 80 | 100 | 125 |
| Rated short-time withstand current (4s) | kA | 31.5 | 40 / 31.5 | 40 | 50 |
| Rated peak withstand current | kA | 80 | 100 / 80 | 100 | 125 |
| Near fault breaking current | kA | 90% lk, 75% lk | – | – | – |
| Rated out-of-step breaking current | kA | 25% lk | – | – | – |
| Creepage distance | cm/kV | 3.1 | 2.5, 3.1 | – | – |
| 1-min power frequency withstand voltage (dry test) | |||||
| – To ground | kV | 160 | 275 | 460 | 460 |
| – Inter-pole | kV | 160 | 275 | – | – |
| – Fracture | kV | 160 + 42 | 275 | 395 + 145 | 395 + 145 |
| 1-min power frequency withstand voltage (wet test) | |||||
| – To ground | kV | 160 | 275 | 460 | 460 |
| – Inter-pole | kV | 160 | 275 | – | – |
| – Fracture | kV | 410 | 650 / 750 | 950 + 206 | 950 + 206 |
| Rated lightning impulse withstand voltage | |||||
| – To ground | kV | 350 | 550 / 650 | 1050 | 1050 |
| – Inter-pole | kV | 350 | 550 / 650 | – | – |
| 5-min zero-pressure withstand voltage | kV | 84 | 95 / 124 | 189 | 189 |
| Closing time | ms | ≤150 | ≤150 | ≤110 | ≤100 |
| Opening time | ms | ≤30 | ≤30 (reclosing ≤35) | ≤30 | ≤25 |
| Breaking time | ms | ≤60 | ≤60 | ≤60 | ≤60 |
| Closing-Opening time | ms | 40-60 | 40-60 | 50-70 | 40-60 |
| Phase asynchronism time | ms | ≤2 (open), ≤4 (close) | ≤2 (open), ≤4 (close) | ≤2 (open) | ≤2 (open) |
| Rated reclosing sequence | – | O—0.3s—CO—180s—CO | O—0.3s—CO—180s—CO | – | – |
| SF6 gas rated pressure | MPa | 0.5 / 0.4 | 0.5 | 0.6 | 0.6 |
| SF6 gas alarm/lock pressure | MPa | 0.45/0.40, 0.35/0.30 | 0.45/0.40 | 0.55/0.50 | 0.55/0.50 |
| SF6 gas annual leakage rate | %/Year | ≤0.5 | ≤0.5 | ≤0.5 | ≤0.5 |
| Number of fractures per pole | – | 1 | 1 | 1 | 1 |
| Mechanical life | Times | 3000 | 3000 | 3000 | 3000 |
| Terminal mechanical strength | |||||
| – Horizontal longitudinal tension | N | 790 | 1250 | 1500 | 1500 |
| – Horizontal lateral tension | N | 750 | 750 | 1000 | 1000 |
| – Vertical tension | N | 750 | 1000 | 1250 | 1250 |
| Main circuit resistance | μΩ | ≤50 | ≤45 | ≤45 | ≤42 |
| Matching mechanism | – | Spring | Spring | Spring/ Hydraulic | Hydraulic/ Pneumatic |
| SF6 gas weight per unit | kg | 4 | 6 | 30 | 30 |
| Circuit breaker weight | kg | 1000 | 1400 | 3500 | 4000 / 4500 |
| Standards compliance | – | GB/T 1984, IEC 60056 | GB/T 1984, IEC 60056 | GB/T 1984 | GB/T 1984 |
