Circuit breakers with residual current protection (CBR) switch high currents, protect equipment, cables and lines from overcurrent and people from electric shock. DFL 8 are compact devices with an integrated auxiliary switch and connection terminals for large cable cross-sections. Type B switches are sensitive to all currents. They protect against pulse and alternating residual currents, residual currents with mixed frequencies and smooth direct residual currents at frequencies up to 150 kHz. They are resistant to increased surge currents and storms. Switches with the SK characteristic curve stand for residual current protection and high system availability. They are characterized by a lower response sensitivity at higher frequencies. Undesired tripping due to leakage currents is thus largely avoided. With switches of this variant, the fault response current can be individually set 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. Devices of version V are designed for special voltages. Properties: - adjustable rated residual current - rated currents from 100A to 250A, - rated voltage 290 V, 500 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 residual currents type B, - mains and auxiliary voltage independent tripping for residual currents of type A and in the event of overcurrent, - high short-circuit switching capacity, - connection terminals up to 185mm - thresholds for instantaneous and delayed overcurrent tripping adjustable - high surge current strength, i.e. low tendency to false tripping due to transient residual currents - auxiliary switch integrated Mounting type: - attachment to mounting plate - installation position as required - feed from below Application areas: - 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 from the mains on the input side. - It cannot be used for residual current protection in TN-C networks