XGN15-12(F) / XGN15-12(F·R) Box-Type Fixed AC Metal-Enclosed Switchgear
XGN15-12(F) and XGN15-12(F·R) box-type fixed AC metal-enclosed switchgear is used in ring network power supply or radial power supply systems with rated voltage of 12kV and rated current of 630A and below. It is especially suitable for installation in prefabricated substations for control and protection of power distribution systems.
The switchgear features a compact fixed-mounting enclosure with modular construction, integrating SF6 load switches or load switch-fuse combination units within a sealed, maintenance-free tank. Its small footprint and lightweight design make it ideally suited for space-constrained prefabricated substations, underground distribution rooms, and outdoor cabinet installations where conventional switchgear cannot be accommodated.
The “F” designation indicates the load switch variant, while “F·R” denotes the load switch-fuse combination, providing integrated short-circuit protection through current-limiting fuse operation.
Technical Specifications
| Item | Specification |
|---|---|
| Rated Voltage | 12kV |
| Rated Insulation Voltage | 12kV |
| Rated Frequency | 50Hz / 60Hz |
| Rated Current (Main Busbar) | 630A |
| Rated Short-time Withstand Current (Icw) | 20kA (4s) |
| Rated Peak Withstand Current (Ipk) | 50kA |
| Rated Active Load Breaking (Load Switch) | 630A |
| Rated Short-circuit Making Capacity | 50kA (peak) |
| Rated Short-circuit Breaking (Fuse Combination) | Up to 31.5kA (via fuse) |
| Degree of Protection | IP3X (enclosure) |
| Installation Type | Indoor, fixed, prefabricated substation-integrated |
| Switching Device Options | FLN36-12D SF6 load switch / FLRN36-12D load switch + fuse combination |
| Operating Mechanism | Manual spring-charged quick-make/quick-break (standard) / Electric motor (optional) |
| Mechanical Endurance | ≥ 5,000 operations (load switch) |
| SF6 Gas Pressure (20°C) | 1.4 bar (absolute) |
| Gas Leakage Rate | ≤ 0.1% per year (sealed for life) |
| Maintenance Interval | Sealed for life — maintenance-free |
| Standards | GB 3804, GB 16926, IEC 62271-103, IEC 62271-105 |
Key Features
- Ring Network & Radial Distribution Optimized: Specifically designed for 12kV ring main unit (RMU) and radial distribution systems, supporting both looped and open-ring operating configurations common in urban underground cable networks
- Sealed SF6 Load Switch Technology: FLN36-12D SF6 load switch features rotary arc extinction within a hermetically sealed stainless steel tank — completely maintenance-free with no gas handling required over the equipment lifetime (leakage rate < 0.1% per year)
- Integrated Fuse Protection (F·R Variant): The load switch + fuse combination variant provides high short-circuit breaking capacity (up to 31.5kA through the fuse) while maintaining compact enclosure dimensions — the striker pin triggers all three-phase tripping when any single fuse operates
- Compact Prefabricated Substation Integration: Small dimensions and lightweight construction make it the preferred HV switching and protection device for installation inside prefabricated box-type substations, container substations, and outdoor distribution cabinets
- Maintenance-Free Operation: All primary components are sealed within the SF6 tank, eliminating the need for periodic servicing — no contact replacement, no insulation cleaning, no lubrication required over the product service life
- Quick Operating Mechanism: Spring-charged quick-make / quick-break mechanism ensures specified making and breaking speeds independent of operator action speed, with clear position indication visible through the panel window
- Reliable Interlocking System: Mechanical interlocks between the load switch, earthing switch, and panel door prevent incorrect operating sequences — the panel door cannot be opened with the load switch closed, and the earthing switch cannot be closed with the load switch closed
- HV Cable Compatibility: Supports a wide range of cable termination types — heat shrink, cold shrink, and plug-in separable connectors up to 630A rated current
Applications
- Ring main units (RMU) for urban 10kV underground cable distribution networks
- Prefabricated box-type substations — HV incoming and outgoing protection
- Secondary distribution substations in industrial and commercial complexes
- Wind farm and solar farm auxiliary power and collection systems
- Residential community medium voltage distribution
- Infrastructure projects — tunnels, airports, railways, and highways
- Industrial park distribution and metering points
- Outdoor cabinet-type secondary distribution installations