Combined circuit breaker iCV40N-C25-30-AC C 25A 3-pole 30 mA type AC A9DE3725

Three-phase circuit protection with leakage detection function

The device combines the functions of an overcurrent circuit breaker and a residual current device, providing comprehensive protection for installations against short circuits, overloads, and electric shock. This model is designed for use in 400 V AC networks, where protection of 3-phase circuits is required with simultaneous disconnection of the neutral conductor (N). Thanks to its Type C tripping characteristic, the device is particularly useful in circuits powering motor-driven devices or other loads that generate short-term inrush current spikes, which could cause nuisance tripping in breakers with different curves.

The leakage current sensitivity is 30 mA, which represents a standard level of electric shock protection for domestic and industrial installations. The AC type designation indicates that the device reacts to sinusoidal leakage currents up to 30 mA, covering most typical fault scenarios in single-phase and three-phase installations. It is worth noting that the device operates instantaneously – it has no time delay, ensuring immediate power disconnection the moment a dangerous leakage is detected.

Design and mounting capabilities

The device occupies a width of 5 modules (45 mm) on a DIN rail, allowing for efficient use of space in modular distribution boards. Its design enables the connection of wires with cross-sections from 1 to 16 mm² (rigid) and from 1 to 10 mm² (flexible), providing great flexibility during installation work. The installation depth is 44 mm, and the IP20 protection rating guarantees safety against contact with live parts when standardly mounted in a distribution board enclosure.

The device is equipped with a mechanical lock, which allows the breaker to be secured against accidental or unauthorized switching on after being turned off – this function is crucial during service or renovation work. Additionally, the device features a visual indicator of contact position and the possibility of connecting additional accessories (e.g., shunt trips), which increases its versatility in more complex automation systems.

With a breaking capacity of 6 kA, the device safely interrupts even large short-circuit currents occurring in modern networks. In the event of overloads or short circuits, the energy limitation class III ensures rapid quenching of the electric arc, minimizing thermal damage to the cabling. The device can operate in a wide ambient temperature range from -5 to 60 °C, making it suitable for installation in unheated rooms or those with variable temperatures.

Application and operating conditions

The breaker is primarily used in main and sub-distribution boards in residential buildings, offices, and small industrial plants. It is an ideal solution for protecting final circuits powering household appliances, machine tools, or three-phase lighting systems. Due to its high impulse current resistance (0.25 kA) and overvoltage category III, the device also performs well in locations exposed to mains voltage fluctuations or remote atmospheric discharges.

It is worth noting the device's compliance with EN/IEC 61009-2-1 and EN/IEC 60947-2 standards, which confirms its reliability and safety throughout the installation's life cycle. Power losses of approximately 12.9 W indicate moderate self-consumption of the device during continuous operation at full rated load – this is an important parameter when designing large distribution boards with many such devices. Thanks to this solution, the installer receives one component instead of two separate ones (an overcurrent breaker and a residual current device), which simplifies the wiring diagram and reduces the number of potential failure points on the busbar.