Circuit breaker noark Ex9BN 1P B25 — 1-pole B curve, 25 A

Miniature circuit breaker noark Ex9BN 1P B25 is a single-pole protective device with a nominal current rating of 25 A and a B-type tripping characteristic. It is intended for overload and short-circuit protection of single-phase circuits in residential and light commercial electrical installations. The compact design enables mounting on standard 35 mm DIN rails and integration into consumer units and distribution boards where precise and reliable disconnection of phase conductors is required.

Advantages

The noark Ex9BN 1P B25 combines compact dimensions with stable thermal-magnetic tripping performance, offering dependable protection for circuits with predominantly resistive loads. Its B curve sensitivity ensures prompt disconnection of low-magnitude short-circuits while tolerating harmless inrush currents from lighting and small motors. The product is designed for straightforward installation and replacement in standard DIN-rail switchgear, providing a consistent connection interface and clear current rating marking for easy identification.

Suitable for

• Protection of lighting circuits in residential and commercial premises
• Overload and short-circuit protection for sockets and small appliances
• Single-phase branch circuit protection in distribution boards and consumer units
• Circuits with mainly resistive loads and occasional motor inrush currents

Key specifications

• Poles: 1 (single-pole)
• Tripping characteristic: B-type (thermal-magnetic)
• Rated current: 25 A
• Mounting: 35 mm DIN rail compatible
• Application: single-phase circuit protection (phase conductor disconnection)
• Construction: miniature circuit breaker with manual on/off toggle

How to use

Install the miniature circuit breaker on a standard 35 mm DIN rail inside the distribution panel, ensuring the breaker is correctly oriented and securely snapped into place. Connect the incoming phase conductor to the breaker’s line terminal and the outgoing load conductor to the load terminal, following local wiring regulations and ensuring proper torque on terminal screws. After installation, switch the device to the ON position and verify correct operation by testing the protected circuit. For replacement, isolate the supply before removing the device and follow the same wiring sequence when fitting the new breaker.

Usage recommendations

Use the noark Ex9BN 1P B25 in single-phase circuits where a B curve is appropriate—typical examples include lighting circuits and general-purpose sockets with minimal motor loads. Verify that the 25 A rating matches the conductor cross-section and downstream device ratings, and always comply with national electrical codes for installation, earthing, and coordination with upstream protection.