ETI KZS-4M residual current circuit breaker with overcurrent protection 3P+N C 6/0.3A type A 6kA (2174521)

The ETI KZS-4M device is a differential circuit breaker with overcurrent protection designed for use in distribution boards of residential, commercial, and small industrial electrical installations. It combines the functions of a miniature circuit breaker and residual current protection in one housing, which makes it suitable for protecting individual lines against overload, short circuit, and leakage current. With a 3P+N pole configuration, it is intended for three-phase networks with a neutral conductor. The rated current is 6 A, and the C tripping characteristic indicates suitability for circuits with moderate inrush currents. This makes the device appropriate for lighting circuits, socket groups, and other loads where brief starting currents may occur. The rated residual current of 0.3 A provides protection by disconnecting the circuit when a dangerous differential current appears. The breaking capacity of 6 kA allows the unit to interrupt fault currents typical of many household and commercial networks. The residual current protection is type A, so the breaker responds not only to alternating residual current but also to pulsating direct residual current. This is important in circuits supplying equipment with electronic control, rectifiers, and other loads that can produce non-sinusoidal leakage currents. The device operates at a nominal frequency of 50/60 Hz, which supports use in standard electrical systems with either frequency. Connection is possible with conductors from 1 mm² to 25 mm², providing compatibility with a wide range of installation cables and wires. Compliance with IEC/EN 61009 confirms that the product meets the requirements for residual current operated circuit breakers with overcurrent protection. KZS-4M is therefore suitable for protecting separate outgoing lines where coordinated overcurrent and earth-leakage protection is required in a compact modular format.