Hager NDN340 3-Pole Miniature Circuit Breaker 40A 10kA D-Curve

The Hager NDN340 is a robust 3-pole miniature circuit breaker engineered to provide dependable protection for electrical distribution systems. With a rated current of 40A and a high breaking capacity of 10kA, this device is specifically designed to handle the demanding requirements of industrial and commercial environments. It features a D-type tripping characteristic, making it ideal for circuits with high inrush currents, ensuring that the system remains safe and operational under various load conditions while effectively preventing damage from short circuits and overloads.

Advantages

This circuit breaker offers exceptional reliability and safety for complex electrical installations. Its 3-pole configuration allows for the simultaneous disconnection of three phases, providing comprehensive protection for three-phase equipment. The D-curve tripping characteristic is specifically optimized for applications involving motors, transformers, and other inductive loads that generate significant current spikes during startup. The high 10kA breaking capacity ensures that the device can safely interrupt high fault currents, minimizing the risk of fire or equipment damage in the event of a short circuit.

Suitable for

• Industrial machinery and motor control centers
• Commercial electrical distribution boards
• Systems with high inductive loads
• Protection of transformers and power supplies

When it may not be suitable

This device is not intended for residential lighting or standard household outlet circuits, as the D-curve tripping characteristic is too insensitive for these applications. Using this breaker in circuits with low inrush currents may result in a failure to trip during a fault condition, compromising safety.

Key specifications

• Number of poles: 3
• Rated current: 40A
• Breaking capacity: 10kA
• Tripping characteristic: D-curve
• Operating voltage: 400V AC

How to use

The Hager NDN340 is designed for installation on a standard DIN rail within an electrical distribution cabinet. It should be installed by a qualified electrician in accordance with local electrical regulations. The device is mounted by snapping it onto the rail and securing the electrical connections to the input and output terminals. Ensure that the wire gauge used is appropriate for a 40A current rating to prevent overheating at the connection points.

What to consider before purchase

• Verify that the D-curve characteristic matches the startup current requirements of your connected equipment.
• Ensure the 40A rating is compatible with the total load of the circuit.
• Confirm that the installation environment meets the requirements for a 400V AC system.

Usage recommendations

Regularly inspect the circuit breaker for signs of thermal damage or loose connections. It is recommended to perform periodic testing of the tripping mechanism to ensure continued operational integrity within the electrical system.