Circuit breaker Noark Ex9BN 100147 3P C40

The Noark Ex9BN three-pole circuit breaker with C characteristic and a 40 A rated trip setting provides thermal-magnetic protection for distribution circuits. Designed to interrupt overloads and short circuits, this compact device is intended for installation in residential, commercial and light industrial electrical panels where coordinated protection and reliable tripping behavior are required.

Advantages

The Ex9BN 3P C40 features a defined C tripping curve that balances sensitivity to short-circuit currents with tolerance for motor starts and inrush events. Its three-pole design ensures simultaneous disconnection of all phases for safer maintenance and fault isolation. The unit’s compact footprint and standard DIN-rail mounting make it suitable for common distribution boards, while thermal-magnetic operation provides both long-term overload protection and fast magnetic short-circuit release.

Suitable for

• Protection of three-phase branch circuits in residential distribution boards
• Commercial installations with moderate inrush loads (lighting, small motors)
• Light industrial panels where selective thermal-magnetic protection is required

When it may not be suitable

This breaker is not intended for use as a main incomer in high-current distribution systems where higher breaking capacity or different characteristics are required. It may also be unsuitable for installations that demand electronic trip units, adjustable protection curves, or earth leakage detection integrated into the same device.

Key specifications

• Poles: 3-pole (three-phase)
• Tripping characteristic: C curve (thermal-magnetic)
• Rated trip/current setting: 40 A
• Function: Overload and short-circuit protection
• Mounting: DIN-rail compatible

How to use

Install the breaker on a standard DIN rail inside the distribution board, ensuring correct phase orientation and secure terminal connections. Connect supply and load conductors to the corresponding terminals, torque to manufacturer's recommended values, and verify proper tightening and insulation. After installation, switch the breaker on and test circuit continuity and trip operation according to local electrical codes and safety procedures. Perform regular visual inspections and testing as part of preventative maintenance to confirm reliable operation.

What to consider before purchase

• Confirm the required rated current and select a breaker with matching trip setting for the protected circuit.
• Verify the C characteristic is appropriate for expected inrush currents from motors or transformers in the circuit.
• Ensure the device’s breaking capacity and installation environment meet local regulations and load conditions.

Usage recommendations

Use this Noark Ex9BN 3P C40 breaker for branch circuit protection where thermal-magnetic tripping and a C characteristic are appropriate; coordinate with upstream and downstream protective devices to ensure selectivity and comply with applicable wiring practices.