Outdoor Pre-Fabricated Enclosed Ring Main Unit

Product Overview:
The WMXGW-12 outdoor pre-fabricated enclosed ring main unit is an intelligent integrated equipment launched by Wanma Technology Co., Ltd. in response to the latest standards of the State Grid Corporation of China, namely "Technical Standards for Integrated Primary and Secondary Distribution Equipment" and "Standardized Design and Customization Scheme for 12kV Ring Main Units (Boxes)".  It integrates advanced technologies such as voltage and current transformers, partial discharge temperature measurement devices, power loss metering modules, and high-speed fault transient filtering. The product mainly consists of an outdoor enclosure, ring-in/ring-out units, feeder units, busbar equipment units, a centralized DTU unit, and connecting cables. It can collect signals such as current, voltage, frequency, zero-sequence current, active power, line loss metering, partial discharge, and cable temperature. It possesses advanced functions such as line voltage identification, voltage and load limit exceeding detection and reporting, and short-circuit fault detection and processing, meeting the requirements of distribution network automation.

Operating Environment:
Ambient temperature: Maximum temperature 40℃, temperature -25℃, daily temperature difference 25K
Altitude: ≤1000m
Solar radiation intensity: 0.1W/cm²
Pollution level: d
Humidity: Average daily relative humidity ≤95%
Earthquake resistance (horizontal acceleration): 2m/s²
If there are special operating environments different from the above operating conditions, such as high altitude, low temperature, or severe pollution, the user needs to negotiate with the manufacturer during ordering.

Technical Features of the Product:

1. The outdoor pre-fabricated enclosed ring main unit integrates 12kV environmentally friendly gas-insulated switchgear and other primary equipment with secondary components such as the centralized DTU, current and voltage transformers, and metering modules, completing overall assembly and debugging in the factory. It also uses standardized mechanical, electrical, and communication interfaces, avoiding errors and hidden dangers of secondary wiring on site, significantly shortening the on-site installation cycle, and solving the interface compatibility problems caused by the separate installation of traditional primary and secondary equipment.

2. The primary side of the environmentally friendly gas-insulated switchgear abandons the high-temperature greenhouse effect SF6 gas, opting instead for dry air or high-purity nitrogen as the insulating medium. The gas compartment is sealed through laser welding, and a micro-positive pressure design reduces medium loss.  Combined with a vacuum arc extinguishing chamber, it achieves oil-free switching, resulting in short arcing time and low contact wear, meeting the frequent operation requirements of distribution networks.

3. The primary side allows for free combination of different functional units such as circuit breakers, load switches, and voltage transformers, meeting various distribution schemes such as ring-in/ring-out, feeder, and PT applications. The secondary side's centralized DTU can control 4-8 sets of switchgear and supports interlocking control of disconnectors and grounding switches. The equipment supports future functional expansion, such as adding harmonic analysis modules and environmental temperature and humidity monitoring components, making it highly adaptable to both high-density power supply needs in urban core areas and conventional distribution scenarios in rural power grids.

4. It inherits a complete five-prevention mechanical interlocking system, achieving interlocking between grounding switches and cabinet doors, and between circuit breakers and disconnectors, preventing accidents caused by misoperation. The gas compartment is also equipped with an explosion-proof diaphragm, allowing for rapid pressure release in case of abnormal pressure, preventing cabinet rupture. The secondary side DTU adopts a fully industrial-grade design, with an electromagnetic compatibility level of outdoor Class V.  The use of a supercapacitor backup power supply replaces traditional batteries, avoiding battery maintenance problems and ensuring short-term operation of core control functions during power outages, improving system stability.

5. The centralized DTU supports electromagnetic or electronic transformer access, with analog measurement accuracy reaching 0.2-0.5 class. It can collect real-time data such as active power and zero-sequence current, achieving bidirectional metering of forward and reverse active power and four-quadrant reactive power, accurately completing line loss statistics. Some products also use high-frequency sampling at 128 points per cycle to completely record waveform data before and after faults, supporting 64 fault waveform recording cycles.