The FI switch DFS4 040-4/0.03B SK from Doepke is a highly advanced residual current circuit breaker designed for use in single-phase and three-phase networks. It provides reliable protection for people, animals, and electrical systems by automatically interrupting the power supply in the event of dangerously high fault currents. With a compact design that occupies only four modular units, this switch is both space-saving and powerful. It can detect fault currents with frequencies ranging from 0 Hz to 150 kHz, making it particularly versatile. The large double-decker terminals allow for the connection of conductors with larger cross-sections, while the tripped position of the multifunction switch lever significantly facilitates troubleshooting. Additionally, the free labeling software supports easy labeling, simplifying installation and maintenance.

• All-current sensitive for fault currents from 0 Hz to 150 kHz
• High immunity to operational leakage and fault currents starting from 1 kHz
• Suitable for mounting on DIN rails
• Increased surge current and lightning resistance
• Optimized for systems without fire protection requirements.