Residual current circuit breakers (RCCBs) are components for implementing the protective measure of protection by automatically switching off the power supply in accordance with the requirements of VDE 0100 Part 410 or corresponding international installation regulations. Devices in the DFS 4 series are compact two- or four-pole residual current circuit breakers. In the standard version, they only take up four division units. While the DFS 4 version for alternating and pulsating direct residual currents is designed for three-phase networks, but can also be used in single-phase networks, there are special versions for single- or three-phase operation in the universal current sensitive versions (type B, type B+). Despite the compact dimensions, a large number of different tripping currents and characteristics are available for rated currents - depending on the version - up to 125 A. All devices are available in the HD version, which is particularly suitable for use in harsh environments (tunnels, swimming pools, etc.). They also have large double-deck terminals for accommodating large conductor cross-sections, a practical multi-function switch toggle and can be labeled with pre-made labels using free software. DFS 2 and DFS 4 with residual current characteristic B detect smooth DC residual currents as well as all other residual currents of type B in accordance with IEC 60755. The operating voltage required for this is taken from the mains voltage. Correct voltage supply is guaranteed if the voltage between the mains conductors is ? 50 V. Type A residual currents are detected regardless of the mains voltage. Furthermore, these residual current circuit breakers detect residual currents of all frequencies up to 100 kHz without gaps. With this large frequency range of residual current detection, they significantly exceed the requirements of the construction standards for type B residual current circuit breakers. Fault protection in accordance with VDE 0100 Part 410 is provided over the entire frequency range of residual current detection with an appropriate earth resistance. The maximum permissible earthing resistance is calculated as the quotient of the permissible contact voltage and the highest tripping fault current in the entire recorded frequency range. For residual current circuit breakers with the NK characteristic, the tripping frequency response is below the human tolerance limit for damage caused by body currents at different frequencies. For RCCBs with a rated residual current of 30 mA, this means that extensive personal protection is achieved even with fault currents above the rated frequency. With an upper tripping threshold of 300 mA at frequencies up to 100 kHz, significantly more sensitive and far-reaching protection against fire-hazardous earth fault currents is provided compared to the B SK or B+ characteristics. This means that comprehensive fire protection is also possible for electronic equipment with high clock frequencies.The high level of protection provided by the NK characteristic requires a low leakage current design of the system to be monitored.Standard devices are designed for monitoring circuits with a rated voltage of 230 V or 400 V and a rated frequency of 50 Hz.Features: Meets the requirements of the construction regulations VDE 0664-10/VDE 0664-100E/V VDE 0664-110AC/DC sensitive for residual currents with frequencies and mixed frequencies from 0 Hz (smooth direct current) to 100 kHzElectromagnetic compatibility in accordance with VDE 0664-30 and VDE 0839-6-2 (interference immunity for industrial applications)High availability of the voltage-dependent detection of smooth direct residual currents and alternating residual currents with frequencies of 50/60 Hz through full functionality with mains voltages from at least 50 V AC on any two active conductorsMains voltage independent Tripping for type A fault currents, small size for all rated currents, high short-circuit strength, double-sided double-deck terminals for large conductor cross-sections and rails