Residual current circuit breakers (RCCBs) 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 A switches are sensitive to pulse and alternating current. This function is independent of the mains voltage. Buttons for switching off in emergency situations can be connected to residual current circuit breakers in NA version (NA for EMERGENCY STOP), for example. An integrated LED indicates emergency tripping by a button or wire break. The residual current circuit breaker can only be switched on again after the problem has been rectified. Several RCCBs can be connected in parallel. Properties: tripping independent of mains and auxiliary voltage, sensitive for alternating and pulsating direct residual currents (type A), only 1/2 TE wider than the standard device, no additional power supply required for the EMERGENCY STOP circuit, full isolating properties, in the event of a power failure the EMERGENCY STOP function does not trigger, 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', 'tripped', connection C1 neutral conductor position on the left, mounting type: quick fastening on mounting rail, installation position as desired, feed from above, areas of application: RCCBs of the NA series are particularly suitable for systems in which an EMERGENCY STOP circuit with isolating properties is to be provided, such as in classrooms or on production plants. Use in TN-C networks and for protecting systems is excluded. in which electronic equipment can cause smooth DC residual currents or residual currents with frequencies other than 50 Hz. Comprehensive protection is not provided here. For such applications, we recommend our universal current sensitive residual current circuit breakers (type B or B+).