Overview
With the continuous development and progress of society, China’s urban power grids have undergone tremendous changes, with most cities now having established—or in the process of establishing—numerous areas of high electricity load density. The traditional supply model, in which power is delivered directly from 12/24-kV lines (or feeder branches) originating at substations to end users, can no longer meet the demands of urban development. Consequently, a new supply approach has emerged: delivering power to customers via switchgear stations. However, as urban densification intensifies, many of the conventional, civil-engineering-based switchgear stations are now constrained by land availability and urban planning regulations. To address these limitations, a more advanced and practical solution has been developed: outdoor intelligent switchgear stations (outdoor ring-main units). These stations require no civil construction, occupy a small footprint, offer highly flexible configuration, provide a more reliable power-supply scheme, significantly shorten construction, installation, and commissioning times, and reduce overall capital costs.
With the advancement of modern industry, there is an increasing demand for higher levels of automation and intelligence in electrical control equipment. By leveraging modern electronic technology, sensor technology, communication technology, and computer networking, it has become an inevitable trend and a key direction of development to integrate the monitoring, protection, control, and metering functions of power equipment under both normal and fault conditions, thereby achieving efficient management.
The intelligent switchgear station (outdoor ring main unit) incorporates and draws upon advanced foreign technologies to integrate 12/24 kV switchgear, circuit breakers, load switches, current and voltage transformers, 12/24 kV power PTs, switchgear FTUs and RTUs, communication and control units (CCUs), 12/24 kV metering and automatic meter reading systems, USP power supplies, and indicating instruments—all pre-assembled and commissioned—within a mobile, sealed, moisture-proof stainless-steel enclosure. This approach achieves the integration of primary and secondary systems and modular assembly in urban distribution networks, shortens construction timelines, and significantly enhances the reliability of urban power grid operations.

Operating Environment Conditions
◎Altitude: ≤ 1000 m;
◎ Maximum ambient temperature: +40℃;
◎Minimum ambient temperature: -25℃;
◎ Maximum daily temperature range: 25 K;
◎ Indoor relative humidity: daily average ≤ 95%, monthly average ≤ 90%;
◎Seismic Resistance: Ground horizontal acceleration of 0.2g and vertical acceleration of 0.1g acting simultaneously. Resonance, sine wave, and beat wave testing methods are employed; excitation is applied five times, with five waves per excitation and a 2-second interval between each, ensuring a safety factor of no less than 1.67.
The installation location shall be free from gaseous vapors, chemical deposits, dust, contamination, and other explosive or corrosive media that could seriously impair the insulation of the load switch; it is intended for use in ungrounded systems and in 10 kV systems grounded via low resistance or arc-suppression coils.

Technical Specifications