SF6-Free RMU: The Future of Eco-Friendly Medium Voltage Switchgear

Introduction

As a leading SF6-free switchgear manufacturer and SF6-free RMU manufacturer, we at ROCKWILL are engineering the next generation of environmentally friendly switchgear for the global power distribution industry. For decades, sulfur hexafluoride (SF6) has been the standard insulating medium in compact MV switchgear — but with a global warming potential roughly 23,500 times that of CO₂, the industry is accelerating toward SF6 elimination. Our SF6 free ring main unit and SF6-free medium voltage switchgear deliver a direct drop-in solution with zero compromise on protection or interruption performance.

What Is an SF6-Free RMU?

A ring main unit (RMU) is a compact, factory-assembled metal-enclosed switchgear used to protect and distribute electricity in secondary distribution networks. As a trusted ring main unit supplier and ring main unit manufacturer China, we offer a complete range of MV ring main unit products rated from 12kV up to 40.5kV. Our flagship SF6 free RMU is engineered as a true SF6 replacement switchgear and SF6 alternative RMU — matching the load-break, fault-interruption, and busbar ratings of conventional SF6 gear without a single kilogram of greenhouse gas.

Insulation Technologies: Dry Air, Pure Air, Nitrogen, Solid

Our platform covers every SF6-free insulation path:

• Dry air RMU and dry air switchgear — our most popular configuration, using dried compressed air as both insulating and arc-quenching medium. As a dedicated dry air RMU manufacturer and dry air switchgear manufacturer, we have optimized sealing, pressure monitoring, and thermal performance specifically for this technology.
• Pure air RMU / pure air switchgear — using thoroughly filtered, dry ambient air. Our pure air insulated switchgear and pure air ring main unit are rated up to 24kV.
• Pure air insulated RMU — a compact variant combining pure-air busbars with solid-insulated load-break switches.
• Nitrogen insulated switchgear / nitrogen insulated RMU / nitrogen insulated ring main unit — using industrial-grade nitrogen (GWP = 1) for customers who prefer a sealed gas alternative.
• Air insulated RMU and air insulated medium voltage switchgear — traditional air-insulated construction for indoor substations.
• Solid ring main unit and gas insulated ring main unit — we continue to offer solid-insulated and compact gas-insulated designs alongside our SF6-free line for mixed-fleet projects.

Why Dry Air vs SF6?

Engineers often ask us: dry air vs SF6 switchgear — what are the real trade-offs? In short, modern dry air insulation switchgear has closed the performance gap. When customers compare pure air vs SF6 switchgear or evaluate pure air switchgear vs SF6 switchgear, the decisive factors are now lifetime carbon footprint, maintenance burden, and regulatory compliance rather than raw dielectric strength. Our engineering teams publish comparative type-test data in every ring main unit datasheet.

Voltage Ratings & Configurations

Our product line spans:

• 24kV SF6 free RMU and 24kV SF6-free switchgear — the sweet spot for urban distribution networks
• 24kV ring main unit, 33kV ring main unit, 36kV ring main unit, and 40.5kV ring main unit variants for medium- and primary-distribution feeders
• Indoor ring main unit for MV switchrooms and kiosk substations
• Outdoor ring main unit for pole-mounted or pad-mounted applications in harsh environments

All units ship with a detailed ring main unit specification and are certified to ring main unit IEC 62271 (specifically IEC 62271-1, -100, -102, and -200).

Zero GWP, Low Carbon, Green Switchgear

Every unit on our platform is a certified zero GWP switchgear and zero GWP RMU. We position ourselves as a green switchgear and low carbon switchgear partner for utilities, EPCs, and panel builders committed to net-zero grids.

Smart, Digital, Intelligent

Modern distribution demands more than clean insulation: our smart ring main unit, distribution automation switchgear, smart grid switchgear, and intelligent switchgear platforms integrate motorized operators, fault passage indicators, vacuum interrupters, and standard IEC 61850 / SCADA communications — turning a passive switch into a monitored node on the smart grid.

Conclusion

Whether you need a 24kV SF6 free RMU for a new housing development, a dry air ring main unit for an industrial plant, or a full SF6 alternative switchgear retrofit program, ROCKWILL has the product, the certification, and the manufacturing scale to deliver. Contact us today for a tailored ring main unit datasheet for your project.