Circuit breaker noark Ex9BN 3P B 20A 6kA AC (MPN NO014)

The noark Ex9BN three-pole miniature circuit breaker with B characteristic provides overcurrent protection and short-circuit interruption for low-voltage AC distribution circuits. Rated for 20 A nominal current and a breaking capacity of 6 kA, this DIN-rail mountable device is intended for coordinated protection in residential, commercial or light industrial electrical installations. The compact design and standardized mounting allow integration into distribution boards and switchgear systems where reliable, space-efficient protection is required.

Advantages

The Ex9BN 3P B 20A offers precise protection for circuits with moderate inrush currents, combining a B-type tripping curve with stable thermal-magnetic operation. Its 6 kA breaking capacity meets common requirements for service-level short-circuit interruption in low-voltage installations. The device is built for DIN-rail mounting and straightforward wiring, enabling fast installation and replacement in modular distribution panels. Designed for predictable performance, it supports coordinated protection strategies in multi-device switchgear.

Suitable for

• Overcurrent and short-circuit protection in residential distribution boards
• Protection of lighting and socket circuits in commercial premises
• Light industrial circuits where moderate inrush currents occur
• Integration into low-voltage switchgear and coordinated protection schemes

Key specifications

• Poles: 3-pole configuration for three-phase circuits
• Tripping characteristic: B curve (sensitive to small overloads and short-circuits)
• Rated current: 20 A
• Breaking capacity: 6 kA (AC)
• Mounting: DIN-rail compatible for distribution panels
• Operation: Thermal-magnetic trip mechanism
• Application voltage: Low-voltage AC distribution networks

How to use

Install the breaker on a standard DIN rail within the distribution board, ensuring correct orientation and secure fastening. Make electrical connections to the line and load terminals according to wiring diagrams and local regulations, observing torque values for terminal screws. Verify the three-phase supply is correctly connected and that protective earth and neutral conductors are properly terminated elsewhere in the panel. After installation, test the circuit and trip function under load and in controlled conditions to confirm correct operation and coordination with upstream or downstream protective devices.

Usage recommendations

Use this three-pole B-characteristic breaker where sensitive overload protection and reliable short-circuit interruption are required for three-phase circuits. For circuits with high motor starting currents or heavy inductive loads, review selectivity and consider alternative tripping characteristics or coordination with supplemental protective devices. Follow national electrical codes and manufacturer installation guidelines for safe operation and maintenance.