Combination circuit breaker iCV40N-C16-30-AC C 16A 3-pole 30 mA type AC A9DE3716

Three-phase circuit protection with electric shock protection

The device combines the functions of an overcurrent breaker and a residual current breaker, allowing two separate devices to be replaced by a single module mounted on a DIN rail. This is an RCBO (Residual Current Breaker with Overcurrent Protection) type solution, which protects the installation from the effects of short circuits, overloads, and earth leakage currents. Thanks to the use of a C tripping characteristic, the device is suitable for circuits with devices that generate short-term current spikes, such as electric motors or transformers. In the event of detecting a leakage current of 30 mA, the device immediately disconnects the circuit, which is crucial for protecting human life from electric shock via indirect contact.

Application and scope of protection

The device is used in main switchboards and sub-distribution boards in residential, office, and small service facilities where 3-phase protection with simultaneous disconnection of the neutral conductor is required. Its 4-pole construction (3P+N) ensures full isolation of all active and neutral conductors during tripping or manual switching off.

• Electric shock protection: 30 mA sensitivity in type AC effectively detects sinusoidal leakage currents, protecting users from direct contact with live parts.
• Installation protection: The thermal mechanism reacts to long-term overloads, and the magnetic mechanism to short circuits, preventing wire overheating and fire risk.
• Breaking capacity: The rated short-circuit breaking capacity is 6 kA, allowing for the safe disconnection of short-circuit current in typical low-voltage installations without damaging the device itself.
• Grid compatibility: The device operates in AC networks with a rated voltage of 400 V and a frequency of 50/60 Hz; the impulse withstand voltage (Uimp) is 4 kV.

Mounting and design features

Mounting is standard on a DIN rail, and the device width is 5 modules (90 mm), which requires appropriate space planning in the distribution board. The installation depth is approximately 44 mm (total height approx. 93 mm). The device is equipped with a lever lock in the "off" position, allowing it to be padlocked or secured against unauthorized switching on – important during service work.

Wire connection is flexible thanks to tunnel-type terminals that accept:

• Single-core wires with a cross-section from 1 to 16 mm².
• Multi-core (flexible) wires with a cross-section from 1 to 10 mm².

This allows the installer to use both rigid cables and multi-strand flexible wires without the need for ferrules (although their use is recommended to ensure a secure connection). The screw tightening torque is 2 Nm, and the standard length of bare wire required for installation is 14 mm. The IP20 enclosure protection rating ensures safety against finger contact but requires installation in a closed distribution box.

The device is characterized by high operational precision due to energy limitation class 3, which means very rapid extinction of the electric arc during a short circuit and minimization of thermal losses. This is particularly important when protecting medium-load circuits, such as three-phase sockets or smaller motors, where the starting current can many times exceed the rated value (16 A). The AC type guarantees effective detection of only sinusoidal leakage currents, covering most fault scenarios in typical domestic and industrial installations. Full disconnection of phases and neutral (3P+N construction) makes this device an essential component in TN-S and TT systems for three-phase loads. The device maintains operational stability in a wide ambient temperature range from -5 °C to +60 °C, enabling its installation even in unheated technical rooms or garages without the risk of incorrect operation of the thermal mechanism.