SF₆ Gas-Insulated Ring Main Unit (RMU) The SF₆ Gas-Insulated Ring Main Unit (RMU) is a new type of SF₆ gas-insulated medium-voltage switchgear independently developed by Jiangsu Huayu Transformer Co., Ltd. Adopting a modular design, it can be arbitrarily arranged according to different design schemes to realize the perfect combination of common-box units and single gas-box units, thus meeting the flexible application needs of various secondary power transmission and distribution substations for compact switchgear. This series of switchgear is a fully sealed system, with all primary components enclosed in a stainless steel housing, so it is not affected by the environment. It also features reliable operation, safety guarantee, compact structural design (small space occupation), maintenance-free operation and long service life. Having passed the type test of the national-level high-voltage electrical equipment test center, it is widely used in small secondary power distribution station…