Surge protection for direct current
Due to their structure, direct current systems exhibit a different behavior during regular operation and in the event of an error than alternating current systems. Consequently, they require specific surge protective devices. Depending on the installation location and requirements, these SPDs are subdivided into type 1 and type 2 protective devices.More information
- Arrester class in accordance with IEC
- Fault alarm
- Nominal discharge current
- Nominal voltage
- Product type
- Supply system configuration
- Safe operation of DC voltage supply systems thanks to reliable protection against surge voltages
- Highly versatile with a maximum altitude of up to 6,000 m (above mean sea level)
- Space-saving installation due to the compact design
- Excellent level of information provided by mechanical/visual status indicator and remote indication contact
Requirements for surge protection
Surge protective devices for protecting DC applications must be adapted to what are in some cases much more stringent requirements. For use in DC systems with particularly high voltage, an SPD must be designed for up to 1,100 V continuous voltage. This is associated with much more stringent requirements for air clearances and creepage distances, which prevent sparkover between the connection terminal blocks and the conductors connected in them. For DC systems with smaller voltages, the requirements are not quite as stringent. However, here too the clear recommendation is to always select the surge protection for the appropriate voltage.
Fundamental advantages of alternating current and direct current
Alternating current or AC voltage offers two major advantages: It can be easily transformed and switched. During transport, however, reactive power is always transmitted as well, which leads to corresponding transmission losses.
Direct current or DC voltage offers the advantage that the desired voltages are used directly at the corresponding systems, machines, and devices via more efficient DC/DC or DC/AC converters. Complex DC intermediate circuits with AC/DC conversion in frequency converters are no longer necessary. In addition, no reactive power is transported in DC transmission systems. This significantly reduces energy losses during transport.