Circuit breaker C120N-C80-1 C 80A 1-pole A9N18357

Circuit protection for high current applications

This device is designed to protect electrical installations against overloads and short circuits in circuits requiring high rated current. As a C120N series overcurrent circuit breaker, this model handles a working current of 80 A, making it suitable for industrial loads, main distribution boards, or circuits powering high-power equipment. Thanks to the use of a C tripping characteristic, the device exhibits a delayed response to short-term current surges, which is crucial when starting electric motors or transformers, where inrush currents significantly exceed the nominal value and should not cause false tripping.

High switching capacity is one of the most important advantages of this model. Under 230 V (AC) voltage conditions, the device guarantees safe disconnection of short-circuit current up to 10 kA in accordance with EN 60898. At higher voltages, i.e., 400 V, this capacity is 3 kA (in accordance with IEC 60947-2). This parameter allows installation in locations where short circuits are a real risk and short-circuit energy may be high. The energy limitation classification at level 3 means that the circuit breaker effectively limits energy flow during a short circuit, minimizing thermal and dynamic damage in the downstream part of the installation and allowing the use of cheaper cables and accessories below the circuit breaker.

Application and operating conditions

The device is used in low-voltage (AC) distribution boards, both in industrial and commercial environments. It is compatible with networks with a rated voltage up to 415 V and insulation up to 500 V. A wide operating temperature range from -25 °C to 70 °C enables its installation in unheated rooms or in zones with varied climatic conditions. The protection rating IP20 ensures safety against contact with live parts for adults (protection against objects larger than 12 mm), but requires installation in a covered distribution box.

Mounting is performed on a standard DIN rail (width 1.5 modules, approx. 27 mm), which facilitates integration with existing Acti9 modular systems. The device can be expanded with additional accessories (e.g., auxiliary contacts, alarm contacts), increasing its flexibility in building automation or industrial systems. The mounting depth is 44 mm, which should be taken into account when designing the dimensions of the distribution cabinet.

Structural and technical benefits

The circuit breaker's construction has been designed to ensure durability and ease of operation:

• Flexible cable connection: Possibility to connect single-core cables with a cross-section from 1.5 to 50 mm² and multi-core cables from 1 to 35 mm². This solution eliminates the need for additional cable lugs for smaller cables and allows direct connection of thick supply cores.
• Visual status indication: The presence of a green strip physically indicates open contacts, which is important for safety during maintenance work – the installer can immediately see whether the circuit is disconnected from voltage.
• Mechanical durability: The device has been tested for resistance to the duty cycle – it withstands up to 20,000 mechanical cycles, guaranteeing a long service life even with frequent switching (e.g., as a main switch).
• Surge resistance: Overvoltage category IV and impulse withstand voltage Uimp of 6 kV provide protection against the effects of atmospheric discharges or network surges originating from power station transformers.

Key electrical data can be summarized as follows: rated current is 80 A with characteristic C and one protected pole; rated voltage is 415 V AC; switching capacity reaches 10 kA at 230 V and 3 kA at 400 V; energy limitation class is third degree; permissible single-core cable cross-section reaches 50 mm²; operating temperature is in the range -25 ... +70 °C. Thanks to the combination of high short-circuit parameters with universal mounting and a wide temperature range, this model constitutes a solid protective element in demanding electrical applications where standard domestic circuit breakers would be insufficient due to too low rated current or switching capacity.