JGXLH Box Type Fixed AC Metal-Enclosed Switchgear, interdependently designed and developed by Jinguan Electric, is a new ring main unit product for urban power grid renovation and construction. The internal components use the state-of-art products in China. Proved by type test and long-term operation evaluation, this product meets IEC298 standard and GB3906 standard and is equipped with anti-misoperation measures. This ring main unit is suitable for distribution systems with three-phase rated voltage of 10KV and rated frequency of 50Hz in places such as factories and mines, residential buildings, high-rise buildings, schools and parks for accepting and distributing electric energy as well as for ring network power supply and terminal power supply.