FN7-12DR/400A 630A Indoor High Voltage Load Break Switch and Fuse Combination
FN7-12DR/400A 630A Indoor High Voltage Load Break Switch and Fuse Combination is designed for 12kV, 50Hz three-phase AC power distribution systems, combining reliable load switching with fuse-based short-circuit protection. Available in 400A and 630A configurations, it provides flexible protection for different medium-voltage load requirements.
The FN7-12DR is suitable for indoor switchgear, substations, industrial facilities, renewable energy systems, and commercial power distribution networks. Its dependable insulation, short-circuit withstand capability, and optimized load and earthing switch design provide safe operation, reliable fault isolation, and long-term performance in 12kV applications.
Get a QuoteOverview
The FN7-12DR/400A 630A Indoor AC High-Voltage Load Switch is designed for three-phase AC 50Hz power systems with a rated voltage of 12kV. It is primarily used for switching and interrupting load currents and for closing short-circuit currents in medium-voltage power distribution systems.
The load switch provides reliable switching performance and can be configured as a combined electrical apparatus for enhanced protection. When used with the appropriate fuse or protection components, it can interrupt fault currents up to the specified short-circuit level, making it suitable for reliable protection of distribution lines, transformers, and other medium-voltage equipment.
With its compact indoor design and dependable mechanical operation, the FN7-12DR is suitable for indoor switchgear, substations, industrial power distribution systems, and other 12kV applications requiring reliable load switching and short-circuit protection.
Operating Conditions
1. Altitude: ≤ 1000 meters;
2. Ambient Temperature: -25°C to +40°C;
3. Relative Humidity: Daily average ≤95%; Monthly average ≤90%;
4. The ambient air should not be significantly polluted by corrosive or flammable gases, water vapor, etc.
Technical Data
| Type | Item | Parameter |
| Electrical Ratings | Rated Voltage | 12kV |
| Rated Current | 400A / 630A | |
| Insulation Performance | Power Frequency Withstand Voltage (1 min, 50Hz) | Phase-to-phase & Phase-to-ground: 42 kV Isolation Break: 48 kV |
| Lightning Impulse Withstand Voltage (1.2/50 μs) | Phase-to-phase & Phase-to-ground: 75 kV Isolation Break: 85 kV |
|
| Withstand Capability | Short-time Withstand Current (4s) | 400 kA / 630 kA |
| Peak Withstand Current | 12.5 kA / 20 kA | |
| Switching Performance | Load Switch Closing Capacity (Peak) | 31.5 kA / 50 kA |
| Earthing Switch Closing Capacity (Peak) | 31.5 kA / 50 kA |
Key Highlights
- Dual Current Ratings – 400A / 630A
Available in 400A and 630A configurations to meet different medium-voltage load requirements and distribution system designs. - High Insulation Strength
Provides reliable dielectric performance and enhanced safety during normal operation and overvoltage conditions. - Reliable Short-Time and Peak Withstand Performance
Designed to withstand short-duration thermal and dynamic stresses associated with demanding medium-voltage networks. - Optimized Switching and Earthing Design
The integrated load and earthing switch structure supports safe operation, reliable isolation, and efficient maintenance procedures.
Typical Applications
- Urban Power Distribution
Installed in 12kV substations and indoor switchgear panels to improve distribution reliability and support stable power supply. - Industrial Facilities
Used in medium-voltage distribution systems in factories, steel plants, chemical facilities, and other industrial environments requiring dependable switching and fault isolation. - Renewable Energy Integration
Suitable for feeder protection and switching applications in wind farms and solar power stations, supporting reliable grid connection and renewable energy distribution. - Commercial Buildings and Complexes
Applicable to medium-voltage systems in data centers, airports, shopping malls, and other commercial facilities where secure load management and high availability are important. - Rural Electrification and Utility Networks
Used in distribution networks serving villages and remote areas, providing stable switching performance under voltage fluctuations and demanding environmental conditions.
