24kV Ring Main Unit

The 24kV Ring Main Unit is a compact, modular switchgear assembly engineered for medium-voltage secondary distribution networks. It integrates load break switches, vacuum circuit breakers, and earth switches inside a hermetically sealed stainless steel tank or solid dielectric enclosure. Designed for unattended outdoor kiosks and indoor package substations, it ensures continuous grid availability and operator safety across 10kV to 24kV distribution lines. 

Hermetically Sealed Tank: Laser-welded 304 stainless steel tank creates a sealed pressure system isolated from external ambient moisture, dust, and atmospheric pollution.

Compact Footprint: Modular multi-way configurations (such as CCF and CCCF) fit into confined substation spaces, minimizing civil construction requirements.

Anti-Misoperation Interlocking: Five-position mechanical interlocking prevents improper operational sequencing between the circuit breaker, load break switch, and earth switch.

Maintenance-Free Switching: Vacuum interrupters combined with SF6 load break switches eliminate internal contact maintenance throughout the operational lifecycle.

Smart Grid Integration: Pre-engineered mounting for motorized actuators, fault passage indicators (FPI), and RTU compatibility supports remote terminal monitoring and SCADA systems.

Secondary Distribution Networks: Urban and rural power grid ring feed systems.

Renewable Energy Integration: Solar PV power collection stations and wind turbine pad-mount substations.

Industrial & Commercial Facilities: Manufacturing plants, data centers, hospitals, and commercial real estate complexes.

Infrastructure Projects: Railway tunnel power supplies, airports, and municipal water treatment plants.

Configuration Expansion: Extendable or compact non-extendable modular combinations built strictly to project single-line diagrams (SLD).

Automation Package: Optional motorized remote control units, auxiliary voltage transformers, and communication protocols (IEC 60870-5-104 or Modbus).

Enclosure Finishes: Cold-rolled steel plates with outdoor-grade electrostatic powder coating (RAL 7035 standard) or marine-grade stainless steel for corrosive coastal environments.

Cable Entry Options: Bottom cable entry or customized interface heights aligned with regional utility connection standards.

Production utilizes CNC fiber laser cutting machines for sheet metal fabrication, robotic welding cells for gas-tight stainless steel tank enclosures, and automated helium leak detection chambers. Every completed tank undergoes a 24-hour pressure drop test to confirm leakage rates below 0.1% per year. Routine factory acceptance tests (FAT) include high-voltage power frequency withstand tests, micro-ohm resistance measurement of main circuits, and mechanical operation verification on test benches prior to crating. 

Type Tests: Certified in accordance with IEC 62271-200 and IEC 62271-100 standards by ILAC-accredited testing laboratories.

Routine Test Reports: Individual factory test reports issued with every serial number, detailing insulation resistance, circuit resistance, and partial discharge measurements.

Documentation Package: Submittal data includes bilingual operation manuals, dimensional AutoCAD/PDF drawings, electrical schematic wiring diagrams, and recommended spare parts lists.

Packaging: Fumigation-free wooden crates lined with moisture-barrier vacuum foil and desiccant packs, secured on shock-absorbing pallets for international ocean freight.

Lifting & Handling: Built-in lifting lugs and forklift base channels engineered for safe crane rigging and site positioning.

Lead Time: Standard configurations ship within 4 to 6 weeks; engineered-to-order projects require 8 to 10 weeks following drawing approval.