FN21-12D/T630-20, FN21-12DR/T125-31.5 Vacuum Load Switch | Three-phase AC 12kV Distribution System Protection Device

Overview

FN21-12D/T630-20 high voltage vacuum load switch and FN21-12DR/T125-31.5 combination apparatus are used in three-phase AC 12kV, 50Hz distribution systems. They feature compact structure, small size, light weight, long life, strong making and breaking capacity, safety and reliability. When used with fuses (referred to as combination apparatus), they can replace more expensive circuit breakers, and are simple to operate and maintain. FN21-12D/T630-20, FN21-12DR/T125-31.5 Vacuum Load Switch adopts vacuum interrupter with high voltage current-limiting fuse protection, combining the economy of load switches and the breaking capacity of circuit breakers, making it the preferred combination apparatus for 12kV indoor distribution.

Service Environment Conditions

• Altitude not exceeding 1000m;
• Ambient air temperature: -25degC to +40degC;
• Relative humidity: daily average not greater than 95%;
• Places without conductive dust, corrosive gases and water vapor;
• Places without fire and explosion hazards;
• Places without severe vibration, with inclination less than 3deg.

Technical Parameters

Structural Features, Performance (and Outline Installation Dimensions, see figure)

FN21-12 load switch and combination apparatus mainly consist of frame, disconnecting switch (or fuse acting as disconnecting switch), vacuum interrupter, earthing switch, operating mechanism, etc. This product features compact structure, small size, long life, strong making and breaking capacity, and simple operation and maintenance. The vacuum switch is equipped with an electric operating mechanism and an energy storage spring, enabling fast opening and closing operation. The disconnecting switch, vacuum switch, and earthing switch are interlocked to prevent misoperation.

1. Frame 2. Disconnecting blade 3. Fuse 5. Upper bracket 6. Interrupter 7. Earthing blade fixed contact 8. Insulator 9. Earthing blade 10. Earthing spring 11. Opening spring 12. Insulating rod 13. Main shaft 14. Tripping mechanism 15. Secondary shaft 16. Linkage rod 17. Operating mechanism

Note: Load switch does not have fuse (item 3) and tripping mechanism (item 4).

Ensure that FN21-12D/T630-20, FN21-12DR/T125-31.5 Vacuum Load Switch FN21-12D vacuum load switch, during installation, pay attention to the fitting clearance between the fuse striker and tripping mechanism, adjust the spring operating mechanism opening/closing speed to 1.2±0.2m/s, and verify the reliability of the interlock between earthing switch and main switch...