The FKN12A-12D pneumatic load switch and FKRN12A-12D series pneumatic load switch - fuse combination device are suitable for 12kV and below three-phase distribution systems. They serve for controlling and protecting power equipment such as transformers, cables, and overhead lines, particularly in urban/rural grid terminal substations and containerized substations. They are also applicable for control and protection in ring networks and dual radial power supply units.
FKN12A-12D Series Pneumatic Load Switch: Can switch load currents and overload currents.
FKRN12A-12D Series Pneumatic Load Switch - Fuse Combination Device: Can switch load currents, overload currents, and interrupt line short-circuit currents.

| Type | FKN12A-12D |
| Rated Voltage | 12kV |
| Rated Frequency | 50Hz |
| Rated Current | 630A, 125A |
| 1min Power Frequency Withstand Voltage (Phase-to-Ground/Phase-to-Phase) | 42kV |
| 1min Power Frequency Withstand Voltage (Isolation Gap) | 48kV |
| Lightning Impulse Withstand Voltage (Peak) Phase-to-Ground/Phase-to-Phase | 75kV |
| Lightning Impulse Withstand Voltage (Peak) Isolation Gap | 85kV |
| Rated Short-Time Withstand Current (Load Switch) | 20kA, - |
| Rated Short-Time Withstand Current (Earthing Switch) | 20kA |
| Rated Short-Circuit Duration (Load Switch) | 4s, - |
| Rated Short-Circuit Duration (Earthing Switch) | 2s |
| Rated Short-Circuit Making Current (Peak) | 50kA, - |
| Active Load Breaking Current | 630A |
| Closed-Loop Breaking Current | 630A |
| 5% Active Load Breaking Current | 31.5A |
| Cable Charging Current | 10A |
| No-Load Transformer Capacity Breaking | 1250kVA |
| Rated Short-Circuit Breaking Current (Current-Limiting Fuse) | -, 31.5kA |
| Rated Transfer Current | -, 1200A |
| Mechanical Life | 2000 Times |
| Impactor Output Energy | -, 1±0.5J |