Siemens' 8DN8 gas-insulated switchgear is a highly successful product concept, featuring economic efficiency, high reliability, safe encapsulation, high gastightness, long service life, low maintenance costs, good accessibility, and compliance with modern requirements. This switchgear is suitable for power transmission and distribution systems with rated voltages up to 145 kV.
The 8DN8 gas‑insulated switchgear from Siemens is designed for power transmission and distribution with rated voltages up to 145 kV, short‑circuit currents up to 40 kA and normal currents of 3150 A. Its compact, modular construction uses aluminium enclosures, SF6 gas insulation and a low‑weight design that enables installation in space‑constrained or sensitive environments.
The system consists of interchangeable modules such as circuit‑breaker units, high‑speed earthing switches, voltage and current transformers, and various connection modules. Features include high reliability, low maintenance, integrated monitoring, and a spring‑stored energy operating mechanism. Quality is ensured through extensive testing, ISO‑certified processes, and a documented quality‑management system.
| Rated voltage | 72.5 / 145 kV |
|---|---|
| Rated frequency | 50 / 60 Hz |
| Rated normal current (busbar) | 2500 / 3150 A |
| Rated short breaking current | 31.5 / 40 kA |
| Insulating gas | Sulphur hexafluoride (SF6) |
| Expected lifetime | > 50 years |
| Typical bay weight | ≈ 3.1 t |
It is rated for up to 145 kV (with a lower version at 72.5 kV).
Sulphur hexafluoride (SF6) is used as the insulating and arc‑quenching medium.
The switchgear is expected to operate for more than 50 years.
A typical bay weighs about 3.1 tonnes.