Ring Main Units (RMU)

HJ-AM Series (Air-Insulated Metal-Enclosed RMU)

Up to 24kV / Air-Insulated / Highly Customizable

The HJ-AM Series Air-Insulated Metal-Enclosed RMU is the highly reliable and economically optimized foundation for secondary medium-voltage distribution. Utilizing ambient air as the primary insulation medium combined with maintenance-free SF6 load break switches or vacuum circuit breakers, it delivers exceptional operational safety, visible fault isolation, and modular flexibility. It is the definitive cost-effective choice for standard indoor substations.

Ideal for Secondary Indoor Distribution:

✓ Commercial Buildings & Residential Complexes
✓ Light Industrial Parks & Manufacturing Facilities
✓ Urban Secondary Substations & Switching Stations
✓ Infrastructure Upgrades with Strict Budget Controls

HJ-Eco Series (Eco-Gas Insulated RMU)

12kV / 100% SF6-Free / Vacuum Switching / Zero GWP

The HJ-Eco Series Eco-Gas Insulated RMU is the ultimate sustainable solution for medium-voltage distribution. By completely eliminating SF6 greenhouse gas and utilizing a clean, eco-friendly gas mixture (Dry Air or N2) combined with premium vacuum arc extinguishing technology, it delivers a Global Warming Potential (GWP) of strictly less than 1. Designed with integrated smart grid monitoring, it is the premier choice for utility upgrades aiming to meet strict carbon-neutrality mandates without compromising on compact size or reliability.

Ideal for Green Infrastructure & Eco-Conscious Grids:

✓ EU & Global Utilities under strict F-gas (SF6) regulations
✓ LEED-Certified Commercial Buildings & Hospitals
✓ Underground Metro Systems & Public Transportation
✓ Green Smart City Upgrades & Eco-Industrial Parks

HJ-GIS Series (SF6 Gas-Insulated RMU)

HJ-GIS Series (Engineering Model: HSRM16-12)

Product Overview & Application

Product Concept: The HJ-GIS Series is an IEC-compliant, fully-insulated SF6 Gas Ring Main Unit. With all primary high-voltage circuits and switching components robotically sealed inside a stainless-steel tank (IP67), it offers true “Fit and Forget” performance for long-term reliability.

Applicable Scenarios: Compact Secondary Substations (CSS), heavy industrial distribution networks, underground vaults, and extreme coastal environments prone to high humidity and salt spray.

Customization Value: Featuring an infinitely modular extensible design, its compact modules (C, F, V) can be seamlessly combined and expanded on-site to match any complex Single-Line Diagram (SLD) requirement.

HJ-RMU Series Modular Ring Main Unit (Smart Integrated Edition)

12kV-24kV / Factory Pre-Wired / SCADA Hardware-Ready

The HJ-RMU Series Modular Ring Main Unit (Smart Integrated Edition) is an advanced, hardware-ready distribution automation platform designed for modern smart grids. By seamlessly integrating your choice of primary switchgear (Air, SF6, Solid, or Eco-Gas) with secondary terminal units (DTU/FTU) and high-precision sensors directly at our factory, we eliminate complex on-site wiring. It provides a robust, open-architecture foundation for your local system integrators to execute rapid SCADA deployment.

Ideal for Automated Distribution Networks:

✓ Unmanned Remote Secondary Substations
✓ Smart City Grid Self-Healing Networks
✓ Critical Facilities Requiring High Reliability
✓ Renewable Energy Grid Integration Nodes

HJ-SIS Series (Solid Insulated Switchgear)

Up to 24kV / 100% SF6-Free / Solid Insulation / Ultra-Compact

The HJ-SIS Series Solid Insulated Switchgear represents the future of eco-friendly medium-voltage distribution. By replacing SF6 gas with premium epoxy resin vacuum casting, all high-voltage live parts are completely sealed and shielded. It delivers a 100% maintenance-free lifecycle, zero greenhouse gas emissions, and an ultra-compact footprint (starting at just 400mm width).

Engineered for Extreme Environments:

✓ High-Altitude & Extreme Cold Regions
✓ Coastal Areas with Heavy Salt Fog & Humidity
✓ Heavily Polluted Industrial & Mining Sites
✓ Underground Subways & High-Density Urban Hubs