EQUIPMENT FAMILY
Ring main units (RMU)
Browse air-, gas- and solid-insulated ring main units for secondary distribution. Compare the insulation medium and switching arrangement for your network.
HJ-AM Series (Air-Insulated Metal-Enclosed RMU)
The HJ-AM Series Air-Insulated Metal-Enclosed RMU is designed for secondary medium-voltage distribution up to 24 kV. It uses ambient air as the main insulation medium, with SF6 load break switches or vacuum circuit breakers for switching.
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HJ-Eco Series (Eco-Gas Insulated RMU)
The HJ-Eco Series is a 12 kV ring main unit that uses dry air or N2 as the insulating gas and vacuum switching, without SF6 in the primary circuit. C, F and V modules are available, with catalogue rated currents up to 1250 A and short-circuit withstand ratings up to 31.5 kA.
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HJ-GIS Series (SF6 Gas-Insulated RMU)
The HJ-GIS Series (HSRM16-12) is an SF6 gas-insulated ring main unit designed for compact secondary substations, heavy industrial networks, underground vaults, and coastal environments. All primary circuits are sealed in an IP67 stainless-steel tank, supporting long-term reliability. Available modules include load break switch, switch-fuse combo, and vacuum circuit breaker, with ratings up to 24kV and 1250A.
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HJ-RMU Series Modular Ring Main Unit (Smart Integrated Edition)
The HJ-RMU Series Modular Ring Main Unit (Smart Integrated Edition) is a factory pre-wired distribution automation platform for 12kV to 24kV networks. It integrates primary switchgear (air, SF6, solid, or eco-gas) with DTU/FTU terminals and electronic sensors, providing SCADA-ready hardware. It supports multiple communication interfaces and protocols, with IP67 internal connections and a built-in backup battery.
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HJ-SIS Series (Solid Insulated Switchgear)
The HJ-SIS Series is solid-insulated ring main switchgear for distribution systems up to 24 kV. Epoxy-resin insulation avoids the use of SF6 in the primary insulation system, and live parts are sealed and screened. Catalogue configurations start at 400 mm cabinet width; confirm access, maintenance, ratings and IEC 62271-200 test evidence for the offered assembly.
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Available test reports and manuals for the equipment shown on this page.
- HJ-AM · Test report · 17Q2389-S
- HJ-AM · Test report · 17Q2390-S
- HJ-Eco · Test report · 23Q0868-S
- HJ-Eco · Test report · 23Q2489-S
- HJ-GIS · Test report · 19Q2026-S
- HJ-GIS · Test report · 19Q2032-S
- HJ-GIS · Test report · 19Q2033-S
Each report identifies the tested model and configuration. Its results do not automatically apply to every product in a series. The download page explains the scope and includes the original report.