Residual current circuit breakers (RCCB) switch off the power supply when dangerously high residual currents occur. They thus protect people, animals and systems. DFS 4 are two- or four-pole residual current circuit breakers for single- or three-phase networks. In the standard version, the compact devices are four division units wide. They are available with many different residual current types and versions with rated currents of up to 125 A. The large double-deck terminals can also accommodate large conductor cross-sections. The tripped position of the multi-function switch toggle makes troubleshooting easier. The free label software helps with labeling. Type F switches are mixed frequency sensitive. They protect against pulse and alternating residual currents as well as residual currents with mixed frequencies deviating from 50 Hz, regardless of the mains voltage. They are resistant to increased surge currents and storms. Residual current circuit breakers in the audio version ensure uninterrupted sound quality of connected high-quality audio systems. They have a particularly low impedance design and thus enable unrestricted current flow. Properties: sensitive to alternating and pulsating direct fault currents of the mains frequency (type A) as well as alternating fault currents with mixed frequencies other than 50 Hz, high immunity to surge fault currents and mains voltage-driven follow-on current pulses, particularly suitable for protecting high-quality audio components, structural optimization with regard to sound quality, e.g. silver-plated, internal current conductors, silver-plated connection terminals, etc., small size for all rated currents, high short-circuit strength, double-sided double-deck terminals for large conductor cross-sections and rail connection, switch position indicator, viewing window for labeling labels, multi-function switch toggle with three positions: 'on', 'off', 'triggered', connection C1 neutral conductor position on the left, mounting type: quick attachment to mounting rail, installation position can be changed, feed direction can be changed, areas of application: the DFS-Audio is particularly used in circuits with high-quality, audiophile components such as, for example, amplifiers, stereo systems, etc. B. record players, CD players, network streamers, amplifiers, active loudspeakers or even sound systems for theaters, cinemas, etc. A type F residual current circuit breaker ensures high system availability through insensitivity to transient surge currents and reliable detection of alternating and pulsed residual currents of the rated frequency (50 Hz), even if other frequency components are present in the residual current, such as can occur with today's audio devices with transformer or switching power supplies. Notes: Also available as a 60 Hz variant.