DEHNmid
Nominal Discharge Current 10 kA; Line Discharge Class 1
- Metal oxide arrester for medium-voltage systems up to 51 kV
- Nominal discharge current 10 kA (8/20 µs)
- High current withstand capability 100 kA (4/10 µs)
- For indoor and outdoor applications
- High temperature vulcanised (HTV) silicone enclosure
- Best performance in polluted systems
- Very high mechanical bending resistance
- Unbreakable at overloads
- Flexible installation
Type
DEHNmid ... L: "Low Duty" for indoor application (no shield)
DEHNmid ... N: "Normal Duty" for indoor and outdoor application (shield spacing of 45 mm)
DEHNmid ... H: "Heavy Duty" for outdoor application at high pollution level (shield spacing of 30 mm)
DEHNmid ... N: "Normal Duty" for indoor and outdoor application (shield spacing of 45 mm)
DEHNmid ... H: "Heavy Duty" for outdoor application at high pollution level (shield spacing of 30 mm)
Details
- The medium-voltage arresters of the DEHNmid product family are designed for use both at lines and stations. This allows to install the SPDs directly at the tower, the transition point from overhead line to conductor as well as directly at the transformer. The DEHNmid medium-voltage arresters are chosen in accordance with IEC / EN 60099-4.DEHNmid medium-voltage arresters protect against the effects of impermissibly high surges.The active part of the DEHNmid medium-voltage arrester consists of high-quality and thermally very stable ZnO varistor discs. Its continuous U/I characteristics, quick response performance and low residual voltage of ZnO varistor discs make it an ideal component for medium-voltage arresters. The external coating of the active part is decisive for the construction of medium-voltage arresters. High temperature vulcanised (HTV) silicone is used here for permanent protection against environmental influences such as air humidity or pollution layers. The modular design provides a range of advantages for system operation:
- Moulding junctures along the arrester surface, which would be sensitive against predischarges due to pollution, are avoided
- Enclosing of air bubbles, which can cause internal partial discharges by applying special permanent pressure of components against each other, is avoided
- Excellently high specific withstand voltage of the interfaces of the enclosure due to special permanent pressure of the components against each other is provided
- Flashover and creepage distances of the arresters can be modified
- Electrically and mechanically optimised pressure mostly avoids the ageing of the flexibility of plastic and stands for high service life of the SPD Apart from a high quantity of clamps and fixing elements, also different impulse meters can be provided as accessories (with and without integrated measuring scale for recording leakage currents), as well as a corresponding disconnector.There are three types of DEHNmid medium-voltage arresters available for application-specific use. DEHNmid ... L for indoor applications, DEHNmid ... N for outdoor applications and DEHNmid ... H for outdoor applications with especially high pollution level.
