ZW20-12FG/630A Outdoor User Boundary Circuit Breaker | 10kV Overhead Line Automation Protection Equipment

I. Overview

ZW20-12FG/630A Outdoor User Boundary Circuit Breaker (commonly known as watchdog) mainly consists of three parts: vacuum circuit breaker body, intelligent controller, and external voltage transformer (Note: dual-side PT optional in distribution automation ring network lines). The product is widely used as section isolating switches and tie switches in 10kV, 13kV urban and rural distribution network overhead ring lines, and can serve as an automatic switch device for load distribution in ring network lines. In branch lines supplying large users, it can serve as a boundary switch. In feeder overhead distribution networks, it can serve as a recloser and sectionalizer. The boundary circuit breaker features remote management mode, protection control functions and communication functions. It can reliably determine and detect zero-sequence current and phase-to-phase short-circuit fault current within the boundary, achieving automatic removal of single-phase earth faults and phase-to-phase short-circuit faults.

The body switch adopts vacuum arc extinguishing and SF6/N2 mixed gas insulation. The enclosure adopts gas sealing, explosion-proof and insulation structure technology introduced from Japan, Germany and France, with excellent overall sealing performance. The internally filled SF6/N2 mixed gas does not leak and is not affected by the external environment. Its spring operating mechanism has been miniaturized and performance-optimized, with operational reliability far higher than traditional domestic spring mechanisms.

II. Service Environment Conditions

• Altitude: ≤2000m
• Ambient temperature: outdoor -30degC ~ +55degC, annual average 20degC, daily average 30degC
• Relative humidity: 95% (25degC)
• Seismic capability: horizontal ground acceleration 0.3g, vertical ground acceleration 0.15g, simultaneous action for three sine waves, safety factor 1.67
• Seismic intensity: 7 degrees
• Maximum daily temperature difference: 25degC
• Solar radiation intensity (at wind speed 0.5m/s): 0.1W/cm2
• Maximum wind speed: 34m/s
• Maximum ice thickness: 10mm
• Installation location: outdoor, at the user responsibility boundary point of 10kV overhead lines
• Grounding methods: neutral ungrounded, grounded via arc suppression coil and low resistance grounding

III. Main Technical Parameters

3.1 Boundary Circuit Breaker Main Technical Parameters (Table-1)

IV. Product Features

• Ideal equipment for urban and rural network renovation;
• Can be paired with controller to achieve remote control, telemetry and remote adjustment, realizing four-remote functions;
• Flexible and convenient operation: electric charging, electric opening/closing, with manual charging and manual opening/closing, and can be operated remotely at close or long distance;
• Superior interrupting performance: short-circuit current 20kA interrupting up to 30 times;
• Low operating power, high reliability: newly designed small electric spring mechanism, with number of parts and operating power (approx. 30W) reduced to the lowest level;
• Maintenance-free: circuit breaker main circuit, secondary components and operating mechanism are all sealed in SF6 gas (zero gauge pressure), not affected by external environment;
• Reliable sealing performance: mature sealing structure technology ensures reliable sealing;
• Unique incoming/outgoing method: silicone rubber bushings provide ample insulation distance between terminals and excellent external insulation;
• Safe to use: explosion-proof device installed on top of the enclosure, even in case of unexpected internal faults, no high-temperature gas or splashes will leak out.

In addition to the above features, it also has the following four major functions:

• Automatic removal of single-phase earth faults within the user area;
• Automatic removal of two-phase earth faults within the user area;
• Rapid fault location;
• User load monitoring.

V. Product Models

• ZW20-12F/630-20
• ZW20-12FG/630-20
• FZW28-12F/630-20

Note: For ordering, select according to the above requirements. If there are special requirements, please contact the company to determine relevant parameters.