Circuit breaker noark Ex9BN 3P C25 3-pole, type C, 25 A

The noark Ex9BN 3P C25 miniature circuit breaker is a three-pole protective device rated for 25 A and intended for installation on standard DIN rails in distribution boards. It offers type C trip characteristics, combining overload and short-circuit protection for three-phase circuits. The breaker is engineered to safeguard general-purpose circuits, motor inrush currents and lighting loads in residential and commercial electrical installations, ensuring selective tripping behaviour for typical load profiles.

Advantages

The Ex9BN 3P C25 provides reliable overcurrent protection with a compact footprint suitable for space-constrained panels. Its type C characteristic allows stable operation with moderate inrush currents from motors and fluorescent lighting. Designed for straightforward DIN-rail mounting and standard panel wiring, the breaker supports coordinated protection schemes when used with compatible upstream and downstream devices. The construction ensures consistent trip performance and simplified integration into three-phase distribution systems.

Suitable for

• Three-phase general-purpose circuits in residential and commercial panels
• Motor circuits with moderate starting currents (type C characteristic)
• Lighting and small HVAC loads
• Distribution boards and subpanels with DIN-rail mounting

Key specifications

• Poles: 3-pole configuration for three-phase protection
• Rated current: 25 A
• Tripping curve: Type C (suitable for moderate inrush currents)
• Mounting: DIN-rail compatible for standard distribution enclosures
• Protection functions: thermal-magnetic overload and short-circuit protection

How to use

Install the breaker on a compatible DIN rail inside the distribution board, ensuring correct phase sequence and secure tightening of line and load terminals to the manufacturer's recommended torque. Connect the three-phase supply conductors to the input terminals and the load conductors to the output terminals, observing correct wiring practices and local electrical codes. Verify the breaker rating matches circuit wiring and downstream equipment; test the installation by applying supply and confirming normal operation and trip functionality where required.

Usage recommendations

Select the 25 A rating when wiring and connected loads are within the conductor ampacity and expected load profile. For applications with high motor starting currents or specialized protection requirements, evaluate higher characteristic types or additional protective devices. Periodically inspect terminal tightness and overall condition during scheduled maintenance and replace the device if any mechanical or electrical damage is detected.