The LW8(A)-40.5 outdoor AC SF6 circuit breaker is a three-phase AC 50 Hz outdoor high-voltage electrical device that uses SF6 gas as both the arc-extinguishing and insulating medium. It adopts a compressed air arc-extinguishing structure, providing strong breaking capacity. It is widely used in power systems with a rated voltage of 40.5 kV for switching rated currents and short-circuit currents in substations and power plants. It can also be used as a link circuit breaker and for switching capacitor banks. The internal current transformers are used for measurement and protection, making this breaker an ideal product for modernization and upgrades.
The circuit breaker features a compact, floor-mounted, outdoor tank-type structure equipped with a CT14 spring operating mechanism. The mechanism is integrated with the main body, ensuring simple installation, easy commissioning, and reliable operation, making it suitable for frequent operations. Its lifespan exceeds 3,000 operations.
It adopts a compressed air arc-extinguishing structure with strong breaking capability, capable of interrupting a 40 kA fault current up to 12 times, setting a domestic record. The sealing performance is highly reliable, using imported sealing gaskets. The dynamic seal features a “Y”-shaped sealing ring with a spring pressure compensation structure.
The secondary wiring board for the current transformer is supplied by a joint venture, ensuring an annual leakage rate of less than 0.5%. The internal current transformers use microcrystalline alloy materials with high magnetic permeability, achieving an accuracy class of 0.2 or 0.2s. Based on user requirements, up to 12 current transformers can be included. The circuit breaker is capable of no-reignition operation in no-load long lines up to 50 km.
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
Phone: +8613736779975
E-mail: sales@vcbbreaker.com
Address: 66 Punan Road, Yueqing Economic Development Zone, Zhejiang, China
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