ABB Ring Main Unit (RMU) – Compact SF₆-Insulated Switchgear for Medium Voltage Applications

The ABB Ring Main Unit (RMU) is a world-class, compact medium-voltage switchgear solution designed for high-performance power distribution networks. Engineered with advanced SF₆ insulation, sealed-for-life technology, and integrated safety systems, ABB RMUs are suitable for a wide range of utility, commercial, and industrial applications requiring load switching and transformer protection up to 36 kV.

Available in multiple modular configurations (2-, 3-, or 4-panel), ABB RMUs support both fused T-off and circuit breaker switching options, with optional EFI (Earth Fault Indicator), CTs (Current Transformers), and SCADA-ready automation. Built for safety, reliability, and long-term performance, ABB RMUs are IEC-certified and ready for smart grid integration.

Key Features – ABB Ring Main Units

• Voltage Rating: Up to 36 kV
• Insulation Medium: SF₆ gas-insulated
• Switching Options: T-OFF fused or circuit breaker fused
• Cable Terminations: Up to 3 air-insulated cable boxes (varies by model)
• Optional Monitoring: EFI and CTs for protection and metering
• Modular Design: Expandable, extensible panel system for customized layouts
• Enclosure: Sealed-for-life, pressure-tested stainless steel tank
• Internal Arc Protection: Fully arc fault-tested up to IAC AFL standards
• Automation Ready: SCADA/RTU integration via IEC 61850, Modbus, or DNP3 protocols
• Maintenance-Free: No on-site gas handling or refilling required over the unit’s lifespan

Benefits

• Global Reliability Standard
  Proven ABB quality with installations in over 100 countries and trusted by major utilities worldwide.
• Enhanced Operator Safety
  Internal arc-rated construction and interlocking mechanisms reduce operational hazards.
• Compact Footprint
  Ideal for indoor and outdoor installations where space efficiency is critical.
• Smart Grid Compatibility
  SCADA-ready for advanced network monitoring, automation, and remote diagnostics.
• Sealed for Life
  Reduces lifecycle costs and eliminates the need for routine gas maintenance.
• Flexible Configurations
  Customizable to meet specific project requirements—ideal for utility, renewable, or industrial sites.

Applications

• Urban and rural MV distribution networks
• Utility substations and compact switchgear rooms
• Renewable energy (solar and wind) grid connections
• Industrial plants, shopping centres, campuses, and mines
• Smart grid and digital substation upgrades