Differential circuit breaker ETI KZS-2M 2P 40A C 0.03A type A 10kA (2173228)

This differential circuit breaker from ETI, series KZS-2M, is designed to protect electrical circuits against overload, short circuit, and leakage current. It is used in residential, administrative, and commercial networks where combined protection of the line and additional protection against dangerous residual current is required. By integrating the functions of an automatic circuit breaker and a residual current device, it simplifies protection layout in a distribution board and helps reduce the number of separate devices needed in the circuit. The device is rated for a nominal current of 40 A and features a C tripping characteristic, which makes it suitable for circuits with moderate inrush currents. This characteristic is commonly used for lines supplying general-purpose loads, where brief current peaks may occur during start-up. The residual current rating is 0.03 A, providing sensitive protection against electric shock and helping detect leakage currents caused by insulation damage or wiring faults. The breaker is built in a 1+N, 2-pole configuration, allowing simultaneous switching of the phase and neutral conductors. Its breaking capacity of 10 kA enables disconnection of the circuit under high short-circuit currents within the specified performance class. The rated frequency of 50/60 Hz allows use in networks operating at either of these standard frequencies. The permissible conductor cross-section range of 1 mm² to 25 mm² supports flexible installation in switchboard assemblies and makes connection of different wiring sizes more convenient. Type A means the device responds not only to alternating residual current, but also to pulsating direct residual current. This makes it appropriate for circuits with modern electrical appliances and electronic loads, where such current components may appear. The product complies with IEC/EN 61009, the standard governing residual current operated circuit breakers with overcurrent protection. Overall, this device is intended for local protection of individual lines and consumer groups where both overcurrent protection and residual current protection are required in one unit.