CBRs (circuit-breakers with integral residual current protection) are circuit-breakers with a magnetic and thermal overcurrent trip and a residual current trip. The circuit-breaker with residual current trip is used for overcurrent protection of equipment, cables and lines in accordance with DIN VDE 0100-430 and for protection against electrical shock by automatic switch-off of the power supply as per DIN VDE 0100-410. This series contains compact devices for rated currents up to 250 A with integrated auxiliary switch and terminals for large cable cross-sections. The devices are preferably mounted on a mounting plate. Switches with residual current characteristic A are independent of the mains voltage and allow the detection of sinusoidal AC currents and pulsating DC residual currents. For switches of this variant, the residual response current can be individually set in levels for the application in question (0,30 A, 0,50 A, 1,00 A, 3,00 A). The non-response lag time can also be adjusted in levels accordingly. Selective residual current circuit-breakers are therefore possible in systems with stacked distribution boards. Devices in the standard design are intended for monitoring circuits with a rated voltage of 230 V or 400 V and a rated frequency of 50 Hz or 60 Hz.