Description
Technical Comparison Matrix
| Performance Characteristic / Parameter | Medium-Voltage SF6 Gas Ring Main Unit Technical Specifications |
| System Rated Voltage Range | 12 kV – 17.5 kV – 24 kV |
| Rated Operating Frequency | 50 Hz (12 kV and 24 kV) / 50/60 Hz (17.5 kV) |
| Switchgear Architecture and Continuity Class |
• Partitioning Class: PM (Metallic Partitioning) • Service Continuity: LSC2 |
| Lightning Impulse Withstand Voltage (BIL Peak) |
• Direct Earthed: 75 kVp (12 kV) | 95 kVp (17.5 kV) | 125 kVp (24 kV) • Across Isolating Distance: 85 kVp (12 kV) | 110 kVp (17.5 kV) | 145 kVp (24 kV) |
| Power-Frequency Dielectric Withstand (1 min dry) |
• Direct Earthed: 28 kV (12 kV) | 38 kV (17.5 kV) | 50 kV (24 kV) • Across Isolating Distance: 32 kV (12 kV) | 45 kV (17.5 kV) | 60 kV (24 kV) |
| Ingress and Mechanical Impact Protection |
• Indoor Enclosure: IP41 • Outdoor Enclosure (Non-Extensible): IP54 • High-Voltage Component Gas Tank: IP67 • Mechanical Impact Class: IK07 (Indoor) / IK10 (Outdoor) |
| Internal Arc Withstand Capacity | AF / AFL / AFLR Class: 20 kA for 1 s |
| SF6 Gas Medium Properties |
• Annual Leakage Rate: ≤ 0.1% per year • Rated Filling Pressure (at 20°C): 0.4 Bar (G) • Minimum Operating Threshold: 0.1 Bar (G) |
| Environmental Installation Limits |
• Maximum Altitude (No Derating): 1000 m above sea level • Maximum Relative Humidity: 95% (24-hour average) |
| Main Busbar Electrical Rating |
• Continuous Load Rating: 630 A • Short-Time Current Rating: 21 kA (3 s) / 25 kA (1 s) • Peak Withstand Current: 52.5 kA / 62.5 kA |
| Load-Break Switch Performance (L-Function) |
• Rated Operating Current: 630 A • Active Load Breaking: 630 A • Cable / Line Charging Current Breaking: Cable: 10 A to 160 A; Line: 1.5 A • Earth Fault Switching Capacity: 48 A (12/17.5 kV) | 150 A (24 kV) • Main Circuit Short-Time / Peak Current: 21 kA (3 s); Peak: 52.5 kA (up to 54.6 kA at 17.5 kV) |
| Fused Combination Switch (F-Function) |
• Normal Busbar Current: 630 A | Fuse Continuous Current: 200 A • Main Circuit Short-Time / Peak Withstand: 21 kA (3 s); Peak: 52.5 kA • Upstream Earthing Circuit Withstand: 21 kA (3 s); Peak: 52.5 kA • Downstream Earthing Circuit Withstand: 2.5 kA (1 s) |
| Earthing Circuit Performance |
• Short-Time Withstand Current: 21 kA • Short-Circuit Duration: 3 s (12/24 kV) | 3 s at 50 Hz / 1 s at 60 Hz (17.5 kV) • Peak Withstand Capacity: 52.5 kA (up to 54.6 kA at 17.5 kV) |
| Mechanical and Electrical Endurance Ratings |
• Load-Break Switch: Mechanical Class M2, Electrical Class E3 • Fused Switch: Mechanical Class M1, Electrical Class E2 • Earthing Switch: Mechanical Class M0, Electrical Class E2 |
| Drive and Operation Options |
• Local Switching: Manual hand lever • Remote Control: Motorized drive mechanism |
