MCB Miniature circuit breaker Icn=6000A 4P C 32A MCN432

Three-phase circuit protection in industrial and commercial installations

The four-pole miniature circuit breaker with a rated current of 32 A and C characteristic is designed to protect three-phase circuits from the effects of overloads and short circuits. Its breaking capacity of 6 kA (according to IEC 60898-1) and 10 kA (according to IEC 60947-2 at 400 V AC) allows for application in both large-scale commercial installations and industrial environments with elevated requirements.

The C characteristic means that the magnetic trip will act at a current 5-10-times higher than the rated current. This feature ensures the breaker performs well with loads characterized by moderate inrush currents—such as electric motors or transformers—while not reacting to short-term current spikes typical of device startups.

Electrical parameters and behavior under various temperature conditions

The rated current of 32 A is measured at a reference temperature of 30°C. This value changes with ambient conditions—at -15°C it increases to 38.6 A, while at the highest permissible operating temperature (+70°C) it drops to 24.2 A. When designing switchboards, these corrections must be taken into account, especially if the device is to operate in enclosures with limited air circulation or in rooms with elevated temperatures.

The rated operating voltage is 230-400 V AC, the insulation voltage is 500 V, and the rated impulse withstand voltage is 4 kV. The operating frequency is in the range of 50-60 Hz. The total power loss at rated load is 17.60 W, which translates to approximately 3.9 W per pole—important information when planning switchboard ventilation.

Electrical connections and DIN rail mounting

The breaker occupies 4 modules of width on a standard 35 mm DIN rail. The upper connection is made as a traditional screw terminal, while the lower connection uses the biconnect system, allowing for the connection of both solid and stranded wires using a screwdriver or cable ferrules.

Connection cross-section range:

• Solid and stranded wires: 1-35 mm²
• Flexible (fine-stranded) wires: 1-25 mm²

The nominal terminal tightening torque is 2.8 Nm—this value is crucial both for the stability of the electrical connection and to avoid damaging the terminal itself during installation.

An important design feature is the ability to mount the device at any angle (360°), which facilitates switchboard arrangement in tight spaces. Aligned upper and lower terminals allow for aesthetic wire routing and simplify the wiring process.

Operating conditions and compliance with standards

The enclosure protection rating is IP20, which means protection against solid objects >12.5 mm and no protection against water—typical for switchboards installed indoors. The device is adapted for operation in all climatic conditions (protection against air humidity), within a temperature range from -25°C to +70°C, and at altitudes up to 2000 m a.s.l.

The pollution degree according to IEC 60664/IEC 60947-2 is 2, and the I²t energy limitation class is 3—the highest class, signifying minimization of the energy passed during a short circuit, which reduces the risk of damage to protected installation components.

The circuit breaker complies with RoHS directive requirements and possesses an EU declaration of conformity. The manufacturer provides full technical documentation, including declarations of conformity and product environmental profiles (PEP).