Hager MCB 40A Triple Pole Type D Curve NDN340A

Hager NDN340A: 40A 3 Pole D Curve Miniature Circuit Breaker (MCB) with 10kA breaking capacity, built for demanding three-phase distribution boards.

Safety & Reliability

This mini circuit breaker combines overload and short-circuit protection with a trip-free mechanism, so the contacts cannot be held closed against a fault even if someone holds the toggle. That means the circuit always disconnects safely when it needs to, protecting downstream cable and equipment. The green "OFF" position on the toggle gives an unmistakable visual indication of isolation, useful for engineers working on live boards where clear status confirmation matters.

Installation & Compliance

As a genuine Hager miniature circuit breaker, this D-curve MCB is rated to BS EN 60898-2 at 10kA and BS EN 60947-2 at 15kA, giving installers a documented short-circuit rating that satisfies both domestic and industrial specification requirements. It accepts 25mm² flexible or 35mm² rigid conductors, so termination is straightforward on higher-current circuits without needing adaptors or ferrules. At just 3 modules wide, it keeps panel space to a minimum on crowded three-phase boards.

Built for Demanding Environments

Rated at 400V AC with a 500V insulation voltage and 6kV impulse withstand, this device is specified for robust three-phase distribution work rather than light domestic loads. An operating range down to -25°C means it stays reliable in unheated plant rooms, external enclosures, and cold industrial sites. IP20 ingress protection is standard for enclosed panel-mounted MCBs of this type.

Key Features of the Hager Miniature Circuit Breaker NDN340A Include:

• Overload & Short-Circuit Protection With Trip-Free Mechanism
• Clear Green "OFF" Isolation Indication On Toggle
• Accepts 25mm² Flexible & 35mm² Rigid Conductors For Fast Termination
• Compact 3 Module Width Saves Panel Space
• D Curve Tripping Characteristic For Inductive & High Inrush Loads
• Rated Current: 40A
• Poles: 3 Pole (Triple Pole)
• Rated Voltage: 400V AC
• Frequency: 50Hz
• Breaking Capacity Icn: 10kA (BS EN 60898-2)
• Breaking Capacity Icu: 15kA At 400V (BS EN 60947-2)
• Rated Insulation Voltage Ui: 500V
• Rated Impulse Withstand Voltage Uimp: 6kV
• Ingress Protection: IP20
• Operating Temperature: Down To -25°C
• Compliant With BS EN 60898-2 & BS EN 60947-2
• What's In The Box: 1 x Hager NDN340A 3 Pole D Curve MCB

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