Description
Description of FKN12-12(R) Series Pressure-Operated Load Switch
The FKN12-12(R) Series Pressure-Operated Load Switch is a high-performance indoor AC high-voltage switching device, specifically engineered for three-phase power systems with a rated voltage of 12kV and a rated frequency of 50Hz. It is designed to safely and reliably switch on and off load currents, loop currents, no-load transformer currents, and cable charging currents, while also capable of closing short-circuit currents to protect power systems from potential faults.
This series includes two core models to meet diverse application needs: the FKN12-12D/630-20 indoor AC high-voltage load switch and the FKN12-12R.D/125-31.5 indoor AC high-voltage load switch-fuse combination. The latter integrates the breaking function of the FKN12-12D load switch with the SLAJ-12 (XRNT-12) high-voltage current-limiting fuse, enabling reliable breaking of any current up to short-circuit current—with the load switch handling operating currents and the fuse handling short-circuit currents, while the fuse triggers the load switch to open via its striker for coordinated protection.
Crafted with advanced pressure-operated technology, the FKN12-12(R) Series features stable performance, compact structure, and strong environmental adaptability, complying with relevant industry standards. It is an essential component for indoor high-voltage power distribution systems, ensuring safe, efficient, and stable operation of power grids and electrical equipment.
Parameter of FKN12-12(R) Series Pressure-Operated Load Switch
| number | project | unit | FKN12-12D/630-20 | FKN12-12R.D/125-31.5 |
| 1 | rated voltage | kV | 12 | |
| 2 | rated frequency | Hz | 50 | |
| 3 | rated current | A | 630 | 125 |
| 4 | lightning impulse withstand voltage | kV | Ground and phase isolation, 85 | |
| 5 | 1-minute power frequency withstand voltage | kV | Intercontinental 42, Isolated Fault 48 | |
| 6 | rated thermal stability current | kA | 20(4S) | |
| 7 | rated dynamic current | kA | 50 | |
| 8 | rated closing current (peak) | kA | 50 | – |
| 9 | rated short-circuit breaking current | kA | – | 31.5 |
| 10 | rated transfer current | kA | – | 1.5 |
| 11 | Maximum breaking current (reference value) | kA | 1.8 | |
| 12 | open circuit no-load transformer capacity | kva | 1250 | |
| 13 | rated cable charging current | A | 10 | |
| 14 | rated active load current interruption count | time | >100 | |
| 15 | Time of load switch tripping by impactor | S | – | >0.06 |
| 16 | thermal stability current of the grounding electrode | kA | 20(2S) | 20(2S) |
| 17 | peak thermal stability current of grounding switch | kA | 50 | 50 |
| 18 | motor operating voltage | V | AC220、DC48 | |
Feature of FKN12-12(R) Series Pressure-Operated Load Switch
- Precise Pressure-Operated Control: Adopts an advanced pressure-operated mechanism, ensuring smooth and reliable switching operations, with accurate control over various types of currents (load, loop, no-load transformer, etc.) and stable performance under long-term operation.
- Dual Protection Design (Combination Model): The FKN12-12R.D variant integrates a load switch and a high-voltage current-limiting fuse, realizing coordinated protection—the load switch handles normal operating currents, the fuse quickly breaks short-circuit currents, and the fuse striker triggers the load switch tripping to avoid secondary faults.
- Strong Environmental Adaptability: Designed to meet strict indoor operating conditions, with excellent resistance to temperature changes, humidity, and pollution; for environments beyond standard requirements, customized solutions can be provided through manufacturer-user negotiation.
- Compact & Space-Saving: Adopts a compact structural design, occupying a small indoor space, which is convenient for installation in limited power distribution rooms and easy to integrate with existing power distribution systems.
- High Safety Performance: Equipped with a reliable grounding switch (optional for load switch models), capable of withstanding short-circuit currents, effectively preventing electric shock and equipment damage, and ensuring the safety of operators and power systems.
- Easy Installation & Maintenance: Mature structural design, simple installation process, and low later maintenance requirements; key components are easy to inspect and replace, reducing maintenance costs and downtime.
- Wide Compatibility: Suitable for various indoor 12kV high-voltage power distribution scenarios, compatible with different power grid configurations, and can be flexibly matched with transformers, cables, and other electrical equipment to meet diverse application needs.
