Below is an introduction to the structural characteristics of the high-voltage ring main unit (HV RMU) body:
1

、The HV RMU adopts a new-type ring network switch unit. The main circuit switch features a multi-circuit common-tank structure, with all electrical main circuits encapsulated in a stainless steel tank and insulated by SF₆ gas. It boasts the characteristics of small size, compact structure, powerful functions, multiple circuit schemes, easy installation, convenient operation, and maintenance-free performance.
2
、The thickness of the stainless steel for the SF₆ gas tank is ≥3.0mm, and the gas tank has excellent airtightness with an annual leakage rate of less than 0.025%, ensuring no gas refilling for 20 years. The switches and blades of the HV RMU are equipped with interlocking devices, fully meeting the "five-prevention" requirements.
3、The tank is equipped with an SF₆ gas pressure gauge and an inflation valve for real-time gas pressure inspection. A low-pressure alarm device is reserved, which can be remotely transmitted to the control center via FTU (Feeder Terminal Unit).
4、Flexible combination modes are available. Circuit breaker units, load switch units, switchless through units, internal sectioning units, etc., can be arbitrarily combined within one gas tank.
5
、The load switch adopts SF₆ gas insulation and a compressed air arc-extinguishing device. The vacuum switch is a vacuum arc-extinguishing switch built into the SF₆ insulating gas.
6、The vacuum switch is protected by a microprocessor-based protection device, featuring overcurrent and quick-break protection functions. It can sensitively detect faults and cut off faulty lines, and is equipped with measurement functions and fault recording functions. An RS-232 interface shall be reserved, with multiple I-T characteristic curves available for users to set protection parameters as needed.
This article is edited and organized by DAYA Electric Group Co., Ltd. (https://www.hygraphics.com/). Please indicate the source when reprinting.