LW58-12 Primary And Secondary Fusion SF6 Column Mounted Circuit Breaker

Overview

LW58-12KV outdoor pole-mounted SF6 circuit breaker is a product developed by our company in response to the new requirements of the State Grid's 10kV primary and secondary integrated pole-mounted circuit breaker access to the grid. The switch configuration fully meets the State Grid's primary and secondary integrated requirements, facilitating the State Grid's unified procurement and batch production. The switch has a compact structure, reasonable layout, and complete functions. All indicators meet the State Grid's primary and secondary integration requirements; it uses unified parameter protection CT, zero-sequence CT and zero-sequence voltage sensor, which has the characteristics of wide measurement range, high measurement accuracy and high reliability. The complete analog quantity facilitates accurate judgment of various line faults.

Normal use conditions

● Ambient air temperature: from -40°C to +70°C;

● Altitude: not more than 4000m;

● Pollution level: IV, the surrounding air can be polluted by dust, smoke, corrosive gas, steam or salt mist;

● Wind speed does not exceed 34m/s (equivalent to 700Pa on the surface of the cylinder); 

● Vibration or earthquake from outside the switchgear and control equipment is negligible;

● The amplitude of electromagnetic interference induced in the secondary system does not exceed 1.10kV.

Structural features

1. Circuit breaker body:

1.12kV pole-mounted sulfur hexafluoride circuit breaker, rated current breaking current 630A-20KA. Equipped with electric spring operating mechanism, operating voltage DC 24V. Insulation resistance to ground is greater than 1000MΩ.

2. The circuit breaker box is made of 3mm 304 stainless steel, with a protection level of IP67; there are obvious open and closed position indicators on the shell that are easy to observe on the ground. The indicator is reliably connected to the operating mechanism, and the indication action is reliable. A rust-proof grounding screw with a diameter of 12mm should be used, and the grounding point is marked with a grounding mark. The surface of the shell is raised and will not retain water for a long time. The shell is equipped with a carrying handle to avoid pulling the outlet bushing, and is equipped with a lifting ring to keep the suspended switchgear horizontal. There is no friction contact between the lifting chain and any part to avoid scratching the spray layer on the surface of the box during the lifting process. The nameplate is made of 304 stainless steel, which is wind and rain resistant and corrosion resistant, ensuring that it is clearly visible during use. The content of the nameplate meets the requirements of relevant national standards.

3. The circuit breaker is equipped with a three-phase Current Transformer + a zero-sequence current transformer: Current transformer ratio: phase current 600/5; zero-sequence current 20/1. Accuracy level: measurement accuracy is 0.5S level, protection 5P10; zero-sequence-secondary input current 1A~rated current, error is less than or equal to 3%, primary current 100A, error is less than or equal to 10%. Zero-sequence current accuracy level is level 1. Phase current rated capacity: 10VA; zero sequence: ≥0.5 VA, meeting the matching requirements (considering the 12-meter cable length, in conjunction with FTU and line loss module, to meet the line loss measurement and fault judgment requirements).

4. The configuration and interface adopt a common box structure and spring mechanism. The circuit breaker has a built-in set of current transformers, providing la, Ib, Ic, and l0 current signals; the circuit breaker has a built-in set of zero-sequence voltage sensors. Aviation sockets, aviation plugs and cables should adopt a fully sealed waterproof structure, and the welding wire side needs to be sealed with insulating materials.

5. Requirements for outgoing line Terminals: The 10kV primary and secondary integrated pole-mounted circuit breaker adopts Terminal outgoing line method. The switch incoming and outgoing line wiring terminals are reserved according to the size requirements in the figure below.