8DN9 type gas-insulated switchgear is a new type of gas-insulated switchgear developed by Siemens. It has high cost-effectiveness and is mainly used in 245 kV and below voltage levels of power distribution systems. The cabinet adopts metal sealed structure, which has high reliability, high safety, low maintenance cost, high cost performance and other characteristics
The 8DN9 gas‑insulated switchgear combines a compact design with high reliability, low operating costs and a long service life. It uses SF6 gas for insulation and arc‑quenching, offers modular construction, and can be installed in sensitive environments such as residential areas.
The document describes the modular system, circuit‑breaker and interrupter units, disconnecting and earthing switches, instrument transformers, and termination modules. Technical data for voltage, current, impulse withstand ratings, leakage rate, temperature range and expected lifetime are provided.
| Rated voltage | up to 245 kV |
|---|---|
| Rated frequency | 50/60 Hz |
| Power frequency withstand voltage (1 min) | 460 kV |
| Lightning impulse withstand voltage (1,2/50 µs) | 1,050 kV |
| Switching impulse withstand voltage (250/2500 µs) | 850 kV |
| Rated normal current (busbar) | up to 3,150 A |
| Rated normal current (feeder) | up to 3,150 A |
| Rated short‑breaking current | up to 50 kA |
| Rated peak withstand current | up to 135 kA |
| Leakage rate per year and gas compartment | ≤ 0.5 % |
| Ambient temperature range | –25 °C to +40 °C |
| Expected lifetime | > 50 years |
| Switchgear type | 8DN9 |
It is rated for voltages up to 245 kV.
The switchgear can break short‑circuit currents up to 50 kA.
Sulphur hexafluoride (SF6) is used as the insulating and arc‑quenching medium.
The expected lifetime is greater than 50 years.