SF6-Free 12kV Solid Insulated Ring Main Unit

Solid Insulated Ring Main Unit

SF₆-free epoxy cast with flexible busbar for maintenance-free, compact urban and industrial networks.

Overview

Key Applications

Why Choose？

Engineering

Technical Specifications

Customization

Support

Overview

The TSTY Solid Insulated Ring Main Unit redefines 12kV secondary distribution by embedding all primary live parts within vacuum-cast epoxy resin modules, operating at atmospheric pressure with dry air as the external insulating medium. Distinct from gas-sealed or open-air designs, this architecture eliminates SF₆ entirely while providing inherent immunity to humidity, pollution, and altitude derating through fully shielded, grounded solid dielectric barriers.
The system employs standardized flexible busbar connectors that allow on-site reconfiguration of load-break switches, vacuum circuit breakers, and fuse-combination units without specialized tools or engineering redesign. Manufactured via automated casting lines with <5pC partial discharge consistency, each unit is validated for ≥30-year service life under IEC 62271-200, making it the definitive solution for decarbonization-mandated grid upgrades where footprint, safety, and lifecycle cost are equally critical.

Key Applications

These units address 12kV applications where atmospheric-pressure solid insulation, modular field expandability, and zero-GWP compliance differentiate them from pressurized gas or conventional air-insulated alternatives.

Transmission Distribution Urban Cable Network Nodes

Photovoltaic Power Station

Transportation Infrastructure Metro Traction Feeders

Commercial High-Rise Vertical Riser Compact RMUs

Data Center Modular Substation Zero-Emission Gear

Subway Station

Why Choose TSTY Solid Insulated Ring Main Unit?

All units feature touch-safe screened connectors, integrated earthing visualization, and optional digital sensor readiness for future-proof asset management.

Atmospheric-Pressure Solid Dielectric

Epoxy/silicone encapsulation operates at ambient pressure, eliminating gas monitoring, refilling, and end-of-life disposal liabilities; inherently immune to altitude derating up to 4,000m without design modification.

Field-Reconfigurable Flexible Busbars

Standardized plug-in busbar interfaces enable on-site addition/removal of functional modules in <2 hours per bay; no welding, bolting, or dielectric testing required during expansion.

Inherent Environmental Immunity

Fully cast primary modules achieve IP67 internal protection independent of enclosure; validated for C5-M corrosion, -40°C/+85°C thermal cycling, and 95% RH continuous operation without condensation heaters.

Automated Casting Consistency

Robotic epoxy injection ensures <5pC PD level on 100% of modules; mechanical interlock alignment verified in-fixture before curing, guaranteeing ±0.2mm dimensional repeatability across production batches.

Lifecycle-Cost Optimization

Zero scheduled maintenance over 30-year design life; no consumable seals, lubricants, or gas handling equipment required; total cost of ownership 35% lower than SF₆ RMUs over 25-year horizon.

Engineering & Global Compliance

Every TSTY Solid Insulated RMU undergoes rigorous validation aligned with international standards:

Solid Insulation Integrity Testing

Each cast module undergoes individual PD measurement (<5pC @ 1.2Ur) and power-frequency withstand (42kV/1min); batch lightning impulse tests (75kV peak) confirm insulation coordination per IEC 62271-200.

Flexible Busbar Interface Validation

Insertion/extraction cycle testing (≥1,000 mates) verifies contact resistance stability (<50μΩ); thermal rise tests at rated current confirm joint performance under continuous load.

Mechanical Interlock Verification

Five-prevention interlock sequences tested under fault-make conditions; earthing switch short-circuit making capacity validated per IEC 62271-102 to ensure operator safety during energized access.

Environmental Aging Simulation

3,000h salt fog + UV exposure on assembled units confirms surface tracking resistance; thermal shock cycling validates epoxy-silicone interface adhesion over 30-year equivalent aging.

Technical Specifications

Standard configurations for Solid Insulated RMU, 12kV rated voltage, 50Hz, 630A main bus, 20kA/3s short-time withstand, IP67 primary module protection, mechanical life ≥10,000 cycles (VCB)/5,000 cycles (LBS), service life ≥30 years, compliant with IEC 62271-200, GB/T 3906, CE, RoHS, SF₆-free declaration.

Solid Insulated Ring Main Unit

Parameter Item	Unit	Technical Value / Specification
Rated Voltage	kV	12.0
Power Frequency Withstand Voltage (1 min)	kV	42 (Phase-to-phase & Phase-to-ground)
Lightning Impulse Withstand Voltage	kV	75 (Phase-to-phase & Phase-to-ground)
Lightning Impulse Withstand Voltage (Isolating/Vacuum Gap)	kV	48 / 85
Rated Frequency	Hz	50
Rated Current	A	630
Rated Short-circuit Breaking Current	kA	20
Rated Short-time Withstand Current	kA	20 (Main Circuit) / 20 (Earthing Switch) / 17.4 (Earthing Circuit)
Rated Short-circuit Duration	s	4 (Main Circuit / Earthing Switch / Earthing Circuit)
Rated Peak Withstand Current	kA	50 (Main Circuit) / 50 (Earthing Switch) / 43.5 (Earthing Circuit)
Rated Short-circuit Making Current (Peak)	kA	50
Mechanical Endurance	Operations	10,000 (Circuit Breaker) / 3,000 (Disconnector) / 3,000 (Earthing Switch)
Electrical Endurance	Operations	30 (At full rated short-circuit breaking capacity)

Customization & Optional Features

Every TSTY Solid Insulated RMU supports application-specific adaptation through modular manufacturing:

Functional Module Selection

Pre-cast LBS, VCB, fuse-combination, metering, and cable-feeder modules with standardized interfaces; mixed configurations assembled per single-line diagram without custom tooling.

Busbar Topology Adaptation

Straight, angled, or T-type flexible connectors for radial, ring, or double-bus arrangements; rated current options (400A/630A/1250A) based on verified type-test data.

Extreme Environment Packages

Integrated anti-condensation heating for tropical sites; UV-stabilized outer housings for direct outdoor kiosk mounting; arctic-grade mechanism lubricants for -50°C operation.

Digital Readiness Integration

Factory-installed temperature, position, and PD sensors with shielded cabling; Modbus RTU/TCP or IEC 61850 communication cards pre-configured for BMS/SCADA interoperability.

Architectural & Labeling Options

Custom RAL powder coating for building integration; multilingual nameplates and QR-linked digital documentation; phase-sequence color coding per regional standards.

Service & Warranty Extensions

Lifetime module integrity warranty; field-service training kits with spare connector sets; global technical support network covering 80+ countries with 48h response SLA.

Enhanced Safety Accessories

Remote racking adapters for live-front avoidance; arc-flash PPE integration guides; LOTO-compatible lockout points on all operating shafts and earthing links.

Support & Documentation

IEC-compliant datasheets and one-line diagrams

Full type-test reports (lightning impulse, etc.)

Installation, operation & maintenance manuals

Regional technical support: 24/7 engineering assistance + spare parts hubs in Asia, Africa, and the Middle East

SF6-Free 12kV Solid Insulated Ring Main Unit | TSTY

Resource

SF6-Free 12kV Solid Insulated Ring Main Unit | TSTY

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