Insights
SF6 RMU vs Solid-insulated Switchgear — How to Choose
The differences between SF6 gas-insulated, fully gas-insulated and solid-insulated ring main units, and which to specify for your site.
A ring main unit (RMU) is the compact switching node of a 12kV cable network. XSDQ Electric offers three insulation philosophies, and the right one depends on the site, not the price.
SF6 gas-insulated RMU — XGN15-12
A sealed SF6 tank holds the busbar, load switch and earthing switch. Compact and cost-effective for urban cable rings and renewable collection. Rated 12kV, 630A, breaking 20kA (breaker) / 50kA (fuse); tank protection IP67.
Fully gas-insulated RMU — SRM-12C
All live parts sit in a 3mm stainless-steel welded tank with silicone-rubber plugs, fully insulated and fully sealed. Rated 12kV, 630A, breaking 25kA; suited to humid, polluted or space-tight rooms. Design life is quoted over 30 years under 20°C indoor condition.
Solid-insulated switchgear — XGN-12
Main conductors are cast in epoxy resin — full insulation, full sealing, full shielding, maintenance-free. Rated 12kV, live-part sealing IP67, ambient -45 °C to +45 °C, altitude up to 4000 m. Best for high altitude, severe cold, humidity and heavy pollution.
How to choose
- Urban cable ring, normal room → XGN15-12 (SF6 tank)
- Humid / polluted / tight space → SRM-12C (sealed gas)
- High altitude / cold / heavy pollution → XGN-12 (solid-insulated)
- Outdoor cable ring → house any RMU in a KBS-12 outdoor cabinet
All types follow IEC 62271-200 / GB/T 3906-2020. Model pages list the exact rated values: XGN15-12, SRM-12C, XGN-12.
XSDQ Electric — Lu'an Xinsheng Electric Co., Ltd., brand XSDQ Electric.