① urban public distribution system ly2015.2, in residential areas, busy streets when the load increases, the need to increase the capacity of the transformer. Construction site temporary power ②: In the case of existing buildings, to be modified or increased electrical equipment, field operations and supply outdoor workplaces, such as oil, mining, ports, railway stations and so on. General requirements ⑴ simple lighting, under public distribution, the box becomes high voltage wiring is not necessary to set up high-pressure metering program, set only low voltage measurement or no metering, no compensation. Outgoing circuits 4 to 6 times, the use of plastic circuit breaker control and protection; ⑵ power lighting under public distribution, the box becomes a loop with an increase of up to 8 to 12 times, in addition, there should be no power compensation; ⑶ self-dimensional power and exceptional circumstances. Box-type substation small footprint. Generally box-type substation footprint of only 5 to 6㎡ can even reduce 3 ~ 3.5㎡. Suitable for general load-intensive industrial and mining enterprises, the port and residential areas and other places that can make a high-voltage power supply extends to the load center, reducing the radius of the low voltage power supply, reduce losses. Low-voltage power lines less, usually 4 to 6 road. Shorten the construction period the site, less investment. When fully sealed transformers and SF6 switchgear and other new equipment, extend equipment maintenance cycle, even up to maintenance requirements. Novel and beautiful appearance, can be coordinated with the substation surroundings. City electricity sector, the self-dimensional box changes (250kVA or 315kVA above), the provisions necessary to use high-pressure measurement, as well as the occasion, with a large loop including setting an alternate circuit. Under these circumstances, the designer combined electricity producers choose the actual reference samples, to optimize the design. Company Website: http: //www.jilinshengye.com