As we all know, SF6 gas is a greenhouse gas, and its leakage will seriously damage the environment. SF6 gas is stable in the atmosphere for up to 5000 years without decomposition, and its greenhouse effect is 23900 times stronger than that of carbon dioxide. SF6 plays a key role in insulation and arc extinguishing in the gas tank. In case of leakage, the equipment must be immediately powered off for maintenance. If the load switch is operated in the case of SF6 gas leakage, due to the lack of enough SF6 gas for arc extinguishing, the arc can not be extinguished in time, which is very easy to cause explosion accidents. In addition, the equipment lacks the insulation protection of SF6 gas, which easily leads to insulation breakdown during operation. Therefore, SF6 monitoring devices and effective ventilation devices must be provided in the power distribution room or power distribution room. After the equipment is out of operation, the SF6 gas needs to be recovered, and the SF6 leak detection process is relatively complex.

SF6 is mainly used in power grid systems, but with the increasing awareness of environmental protection, a global consensus has been reached to reduce or stop the use of products containing SF6. In the field of medium voltage distribution, it has been tried to replace the traditional SF6 ring main unit with solid insulation ring main unit, but it has not been widely promoted because of the high manufacturing process requirements of solid insulation ring main unit.

The State Grid Corporation of China first included the environmental protection gas ring main unit in the standardized design scheme of 12kV ring main unit (box) in the 2019 edition, and released an updated version in the 2020 edition. By the 2022 edition, the SF6 inflatable ring network cabinet was deleted directly in the scheme, which marked that the State Grid Corporation of China officially no longer used the SF6 ring network cabinet, and the environmental protection gas ring network cabinet began to be applied to the State Grid system on a large scale.

The green gas RMU represents a new generation of truly green RMU technology. All primary live parts are completely enclosed in a stainless steel fully enclosed air box, which is filled with dry air or environmentally friendly gas to maintain a slightly positive pressure state and effectively prevent the invasion of moisture and condensation. The load switch and circuit breaker are designed with advanced vacuum arc-extinguishing chamber to realize full inflation and maintenance-free, which is not affected by the external environment. There is no need to worry about gas leakage, because the insulation and arc extinguishing functions are no longer dependent on gas, and can continue to operate safely even if leakage occurs. This design not only truly achieves environmental protection, but also minimizes the use of epoxy resin insulation materials. After the equipment is out of operation, most of the materials can be recycled, further reducing the impact on the environment.