CBR (Circuit-Breakers with Integral Residual Current Protection) are circuit breakers with a magnetic and thermal overcurrent release and a residual current release. The circuit breaker with residual current protection is used for overcurrent protection of equipment, cables and lines in accordance with DIN VDE 0100-430 and for protection against electric shock by automatically switching off the power supply in accordance with DIN VDE 0100-410. This series consists of compact devices for rated currents of up to 250 A with an integrated auxiliary switch and connection terminals for large cable cross-sections. The devices are preferably mounted on a mounting plate. Universal current-sensitive switches with residual current characteristic B detect smooth DC residual currents as well as all other residual currents of type B in a frequency range of up to 100 kHz. The evaluation unit integrated for this requires an operating voltage that is taken from the mains voltage. The correct voltage supply is guaranteed if there is a minimum voltage of 50 V between just two current paths. The detection of type A residual currents (alternating and pulsating direct residual currents), which is completely independent of the mains voltage, ensures protection even if only one active conductor carries voltage to earth and has an earth fault. For switches with the NK characteristic, the tripping frequency response is below the human tolerance limit for damage caused by body currents with different frequencies. For devices with a rated residual current of 30 mA, this means that extensive personal protection is achieved even with residual 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 characteristic. 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 the system to be monitored to have a low leakage current design. With switches of this variant, the fault response current can be set individually in stages to suit the respective application (0.30 A, 0.50 A, 1.00 A). The limit non-response time can also be set in stages accordingly. This makes it possible to implement a selective residual current protection circuit in systems with staggered distributions. Standard devices are designed to monitor circuits with a rated voltage of 230 V or 400 V and a rated frequency of 50 Hz. Properties: - adjustable rated residual current, - range of types with rated currents from 100 A to 250 A, - rated voltage 230 V, 400 V AC, - four-pole, - residual current detection for smooth direct current as well as alternating and pulsating direct currents,- high tolerance to fluctuations in the auxiliary voltage when detecting type B residual currents, - mains and auxiliary voltage independent tripping in the case of type A residual currents and overcurrent, - high short-circuit switching capacity, - connection terminals up to 185 mm², - high surge current strength, i.e. low tendency to false tripping due to transient fault currents, - thresholds for instantaneous and delayed overcurrent tripping can be set, - auxiliary switch integrated, type of installation: - attachment to mounting plate, - installation position as desired, - feed from below, areas of application: - staggered power supply systems with TN-S, TT and TN-CS networks with high short-circuit power in commercial buildings and industry, - in IT networks the residual current tripping of the CBR can be provided for shutdown in the event of a second earth fault., - due to its universal current sensitive residual current tripping, this universal current sensitive CBR is particularly suitable for protecting systems with electronic equipment that is not galvanically isolated on the input side.