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The FN5-12 High Voltage Load Break Switch is a robust and reliable switching device designed for medium-voltage power distribution systems. This load break switch is engineered to safely make and break load currents under normal operating conditions, providing essential control and protection for various electrical applications. This article provides a detailed overview of the FN5-12, including its key technical specifications and associated fuse parameters.

Key Features and Benefits of the FN5-12 High Voltage Load Break Switch
The FN5-12 load break switch offers several key features that make it a valuable component in electrical networks:
- Reliable Load Breaking: Capable of safely interrupting rated load currents, ensuring operational safety and efficiency.
- Compact Design: Its design allows for installation in various switchgear configurations.
- Robust Construction: Built to withstand the demands of high-voltage environments, ensuring a long service life.
- Integration with Fuses: Can be used in conjunction with fuses for enhanced protection against short-circuit faults (FN5-12D model includes short-circuit making current capacity).
FN5-12 High Voltage Load Break Switch Technical Specifications
The following table details the key technical parameters of the FN5-12 High Voltage Load Break Switch:
Name | Unit | Value |
---|---|---|
Rated voltage | kV | 12 |
Maximum working voltage | kV | 12 |
Rated frequency | Hz | 50 |
Rated current | A | 400 / 630 |
Rated short time withstand current (thermal stability current) | kA/S | 12.5/4 / 20/2 |
Rated peak withstand current (dynamic stability current) | kA | 31.5 / 50 |
Rated closed loop breaking current | A | 400 / 630 |
Rated power loading breaking current | A | 400 / 630 |
5% rated power loading breaking current | A | 20 / 31.5 |
Rated cable charging breaking current | A | 10 |
Rated no load transformer breaking current | Equivalent to 1250kVA transformer no-load current | |
Rated short circuit closing current | kA | 31.5 / 50 |
Load current breaking times | Load/times | 100%/20, 30%/75, 60%/35, 5%/80 |
1min power frequency withstand voltage (RMS), phase-to-phase / isolating fracture | kV | 42 / 48 |
Power frequency withstand voltage between isolating fractures | kV | 53 |
Lightning impulse withstand voltage to ground (peak), phase-to-phase / isolating fracture | kV | 75 / 85 |
Opening/closing operating torque | Nm(N) | 90(80) / 100(200) |
Note: FN5-12D grounded part of the load switch with short-circuit making current capacity. |
Fuse Technical Parameters for FN5-12
The FN5-12 high voltage load break Switch is often used in conjunction with fuses to provide overcurrent and short-circuit protection. The following table outlines the technical parameters for compatible fuses:
Model | Rated Voltage KV | Fuse Rated Current A | Rated Breaking Current KA | Rated Current of Fuse-Element A |
---|---|---|---|---|
RN3 | 12 | 50 | 12.5 | 2, 3, 5, 7.5, 12, 15, 20, 30, 40, 50 |
RN3 | 12 | 75 | 12.5 | 2, 3, 5, 7.5, 12, 15, 20, 30, 40, 50 |
RN3 | 12 | 100 | 12.5 | 2, 3, 5, 7.5, 12, 15, 20, 30, 40, 50 |
RN3 | 12 | 200 | 12.5 | 2, 3, 5, 7.5, 12, 15, 20, 30, 40, 50 |
SDL*J | 12 | 40 | 50 | 6.3, 10, 16, 20, 25, 31.5, 40 |
SFL*J | 12 | 100 | 50 | 50, 63, 71, 80, 100 |
SKL*J | 12 | 126 | 125 | – |
Applications of the FN5-12 High Voltage Load Break Switch
The FN5-12 High Voltage Load Break Switch is suitable for a variety of applications in medium-voltage power systems, including:
- Distribution substations
- Ring main units (RMUs)
- Industrial and commercial power distribution
- Protection of transformers and cables
- Switching of load circuits
The FN5-12 High Voltage Load Break Switch is a reliable and essential component for controlling and protecting medium-voltage electrical circuits. Its robust design and clear technical specifications make it a suitable choice for various applications within power distribution networks. When used in conjunction with appropriate fuses, it provides a comprehensive solution for circuit protection.