Residual current circuit-breakers (RCCB) switch the power supply off if dangerous high residual currents occur. DFS 4 are two-terminal or two-terminal pair residual current circuit-breakers for single- or three-phase networks. In the standard design, the compact devices are just four module widths wide. They are available with many different residual current types and variants for rated currents up to 125 A. The large two-tier terminals can also accommodate large conductor cross-sections. The trip position of the multi-function toggle switch simplifies fault-finding. The free label software helps in the labelling process. Type AC switches only detect AC residual currents. As a result, in Germany they are not approved as residual current operated protective devices. Selective residual current circuit-breakers are used in systems with stacked distribution boards. In case of a fault, the switch in whose system section the residual current is detected switches off. The selective RCCBs provide fire and fault protection (due to indirect contact), but no additional protection (direct contract, personnel protection).

response delay for selective design, high immunity against surge currents and mains-voltage-operated secondary current impulses , tripping not dependent on mains and auxiliary voltage, sensitive to AC residual currents (type AC) , compact design for all rated currents, high short-circuit resistance, double-sided two-tier terminals for large conductor cross-section and busbar, switch position indicator, viewing window for labels, multifunction switch toggle with three positions: "on", "off" and "tripped", Neutral conductor position right

quick fastening to mounting rail, any installation position, supply from any direction

Main distribution boards in extended power supplies with TN-S, TT and TN-C-S systems, such as campsites, marinas, allotment gardens and showrooms. Selective residual current circuit-breakers in most cases protect the cables from the main distribution board to the sub-distribution boards, Not permitted for use in TN-C networks; not permitted for protecting systems in which electronic equipment may cause pulsating or smooth DC residual currents or residual currents with frequencies not equal to 50 Hz. Comprehensive protection is not provided with an RCCB type AC. For these applications we recommend our residual current circuit-breaker type A or our AC/DC sensitive residual current circuit-breaker type B/B+.

To ensure the selectivity of the RCCB, the rated residual current of the selective RCCB must be set at least one level higher than the downstream instantaneous switch.

• Operating instructions
• Data sheet
• Prospectus Power for building sites
• Technical information Derating graph for DFS 2/4
• Technical information dissipation power DFS 2/4
• Prospectus Circuit-breaker overview
• Prospectus DFS HD "heavy duty"
• Dimensional drawing Group view
• STEP file
• Wiring diagram
• Labelling software DFS / DLS