The 8BK20 is a medium‑voltage (7.2‑12 kV) switchgear with withdrawable circuit‑breakers, intended for power stations, substations and industrial applications. The manual describes the product’s design, safety concepts, climate suitability and technical specifications.
Key sections cover personnel safety, operation of the withdrawable section, maintenance procedures, electrical data, climate class guidelines, and details on the central service truck used for moving the withdrawable unit. Standards and specifications are listed, along with contact information for Siemens regional offices.
| Rated voltage | 7.2 kV – 12 kV |
|---|---|
| Rated power‑frequency withstand voltage | 29.92 kV (7.2 kV) / 26.42 kV (12 kV) |
| Rated current of busbars | 4000 A |
Safety is improved by opening and closing the switching device only with the door closed, and by isolating the circuit by moving the withdrawable section while the door remains closed.
The switchgear can be used in climate classes 11, 12 and 13 as defined by IEC 72‑3‑3 and Siemens standard SN 29070.
The withdrawable section is light and can be moved outside the panel using a central service truck, by one person and without tools.