In TN systems, the star point of the feeding transformers is connected to earth through a low impedance and the exposed conductive parts of the electrical installation are connected to the protective earth (PE) of the system. In TT systems, the star point is also connected to earth through a low impedance but the exposed conductive parts of the electrical installation are earthed independently from the system earthing.
In TT systems, one point is connected directly to ground (functional grounding). The exposed-conductive parts of the electrical installation are connected to ground electrodes which are electrically isolated from the ground electrode for grounding the system.
Permissible protective devices:
| Name | Category | Size | Language | Timestamp | D-/B-Number |
|---|---|---|---|---|---|
| Pumped storage hydro power station | Market Segment Brochures | 2.3 MB | EN | 2019/07/2525.07.2019 | |
| NON-STOP QUALITY for the production of nonwovens | Technical Article | 287.0 KB | EN | 2022/06/2222.06.2022 |
