DX3 4P 40A Curve C 6/10kA Circuit Breaker

The Legrand DX³ 407932 circuit breaker is a four-pole miniature circuit breaker designed to protect electrical installations against overloads and short circuits. It features 4 protected poles, a rated current of 40 amperes, C curve tripping characteristic, and a rated voltage of 400 volts AC.

This model offers a breaking capacity of 6 kA at 400 volts according to EN 60898-1 and an ultimate breaking capacity of 10 kA at 400 volts according to IEC 60947-2. Its 4-module format and DIN rail mounting make it easy to integrate into residential, commercial, and other electrical distribution panels.

Legrand DX³ 4-pole 40 amp circuit breaker

Reference 407932 is part of Legrand's DX³ range of miniature circuit breakers. Its four-pole configuration allows the 4 poles of the circuit to be protected simultaneously by a single device.

The circuit breaker combines thermal protection against overloads with magnetic protection against short circuits. When it detects an overcurrent that exceeds the circuit's permissible conditions, the mechanism automatically opens the contacts to limit the electrical and thermal effects on the installation.

C curve with magnetic threshold between 200 and 400 amperes

The Legrand 407932 features a C curve tripping characteristic. In this type of breaker, magnetic tripping against short circuits occurs between 5 and 10 times the rated current.

As a 40 amp circuit breaker, the magnetic tripping threshold indicated by Legrand is between 200 and 400 amperes. This characteristic allows certain short-duration transient currents while still providing a fast response to high short-circuit currents.

6 kA breaking capacity according to EN 60898-1

For installations covered by EN 60898-1, the breaker has a rated breaking capacity Icn of 6 kA at 400 volts.

This value indicates the circuit breaker's ability to interrupt a short-circuit current under the test and operating conditions established by that standard.

10 kA breaking capacity according to IEC 60947-2

According to IEC 60947-2, the Legrand DX³ 407932 offers an ultimate breaking capacity Icu of 10 kA at 400 volts. At 230 volts, the specified ultimate breaking capacity reaches 25 kA.

For this reason, the commercial designation 6/10 kA refers to breaking capacities determined according to different standards and test conditions.

Overload protection

The integrated thermal protection acts when a current above the rated value is maintained for a certain period. This function helps prevent excessive heating of conductors and other components caused by prolonged overload.

The operating time depends on the overload current, in accordance with the operating characteristics established for the circuit breaker.

Fast short-circuit protection

In the event of a high short-circuit current, magnetic tripping acts quickly to open the circuit. The combination of both mechanisms provides thermal and magnetic protection in a single modular device.

The Legrand 407932 also features energy limiting class 3, according to the technical data provided by the manufacturer.

4 protected poles

This circuit breaker has 4 total poles and 4 protected poles. The simultaneous opening of the poles allows the circuit to be disconnected at the same time when the device trips.

Its four-pole configuration is intended for installations that require protection of four conductors within a single circuit breaker.

Rated voltage of 400 volts

The device is designed for a rated voltage of 400 volts AC and for frequencies between 50 and 60 hertz.

The rated insulation voltage is 500 volts, while the rated impulse withstand voltage reaches 4 kV.

Modular DIN rail format

The Legrand DX³ 407932 is designed to be installed on a DIN rail inside electrical panels. It occupies a width equivalent to 4 modules.

Its modular format allows it to be installed alongside residual current devices, contactors, control devices, differential blocks, and other compatible elements commonly used in electrical panels.

Dimensions of the Legrand 407932

The circuit breaker has approximate dimensions of:

• Width: 70.8 mm.
• Height: 94.8 mm.
• Depth: 77.8 mm.
• Installation depth: 44 mm.

These dimensions correspond to its four-pole, 4-module configuration and should be taken into account when sizing the available space in the electrical panel.

Top or bottom supply

One of the features of the DX³ range is wiring flexibility. The Legrand 407932 can receive electrical supply from the top or from the bottom.

The manufacturer provides for different connection systems using copper cable and compatible distribution combs. It can use pin combs from the top or bottom, fork combs from the bottom, and compatible HX³ plug-in systems from the top.

Terminals for rigid and flexible conductors

The circuit breaker's terminals are designed to accommodate different conductor cross-sections:

• Flexible or stranded conductors: from 1.5 to 25 mm².
• Rigid conductors: from 1.5 to 35 mm².

The connections use screw terminals, providing a suitable wiring system for installation in electrical panels.

IP20 protection

The circuit breaker has an IP20 protection rating and a terminal design protected against accidental finger contact when correctly installed.

The impact resistance indicated by Legrand is IK02.

Wide operating temperature range

The Legrand 407932 is designed to operate in an ambient temperature range between -25 and 70 degrees Celsius. For storage, the manufacturer specifies a range between -40 and 70 degrees Celsius.

The product also has a pollution degree 2 according to its technical characteristics.

Compatible with auxiliary devices

The circuit breaker supports the addition of compatible auxiliary devices from the Legrand DX³ range. This makes it possible to expand control, signaling, or actuation options according to the configuration planned for the electrical panel.

The DX³ range also allows the use of certain differential blocks and compatible actuation systems, always checking the references approved for each configuration.

Integrated label holder

The front includes a label space that allows the protected circuit to be identified directly in the electrical panel.

This feature makes commissioning, inspection, and maintenance easier in installations with numerous protection devices.

Halogen-free construction

Legrand specifies that this reference uses a halogen-free construction. The exterior finish is grey, corresponding to RAL 7035.

Technical characteristics of the Legrand 407932

• Brand: Legrand.
• Range: DX³.
• Reference: 407932.
• EAN: 3245064079327.
• Product type: miniature circuit breaker.
• Total number of poles: 4.
• Number of protected poles: 4.
• Rated current: 40 amperes.
• Tripping curve: C.
• Magnetic tripping threshold: between 200 and 400 amperes.
• Rated voltage: 400 volts AC.
• Frequency: between 50 and 60 hertz.
• Breaking capacity Icn according to EN 60898-1 at 400 volts: 6 kA.
• Breaking capacity Icu according to IEC 60947-2 at 400 volts: 10 kA.
• Breaking capacity Icu according to IEC 60947-2 at 230 volts: 25 kA.
• Rated insulation voltage: 500 volts.
• Impulse withstand voltage: 4 kV.
• Energy limiting class: 3.
• Pollution degree: 2.
• Number of modules: 4.
• Mounting: DIN rail.
• Installation depth: 44 mm.
• Width: 70.8 mm.
• Height: 94.8 mm.
• Depth: 77.8 mm.
• Protection rating: IP20.
• Impact resistance: IK02.
• Flexible conductor cross-section: between 1.5 and 25 mm².
• Rigid conductor cross-section: between 1.5 and 35 mm².
• Connection type: screw terminal.
• Supply direction: top or bottom.
• Operating temperature: between -25 and 70 degrees Celsius.
• Storage temperature: between -40 and 70 degrees Celsius.
• Color: grey RAL 7035.
• Halogen-free: yes.
• Label holder: yes.
• Compatible with auxiliary devices: yes.

Four-pole protection for electrical panels

The Legrand DX³ 407932 circuit breaker combines a rated current of 40 amperes, C curve tripping characteristic, and protection on 4 poles with breaking capacities of 6 kA according to EN 60898-1 and 10 kA according to IEC 60947-2 at 400 volts.

Its 4-module format, DIN rail installation, top or bottom supply, wide conductor connection range, and the possibility of adding auxiliary devices make it easy to integrate into electrical panels that require protection against overloads and short circuits.