DX3 Circuit Breaker 4P 32A Curve C 6/10kA

The Legrand DX³ 407931 miniature circuit breaker is a 4-pole, 32-amp automatic circuit breaker designed to protect electrical installations against overloads and short circuits. It features a C tripping curve, a rated voltage of 400 volts AC, and a breaking capacity of 6 kA according to EN 60898-1 and 10 kA according to IEC 60947-2 at 400 volts.

Its four-pole configuration with 4 protected poles, DIN rail mounting and 4-module width make it easy to integrate into electrical panels. In addition to providing thermal-magnetic protection, it also enables circuit control and isolation functions.

Legrand DX³ four-pole 32-amp miniature circuit breaker

Reference 407931 is part of Legrand’s DX³ range. The device combines two complementary tripping systems to protect the conductors and equipment of an electrical installation against overcurrents.

Thermal protection responds to sustained overloads over a certain period, while magnetic protection acts quickly when a high current caused by a short circuit occurs.

4 protected poles

The Legrand 407931 has 4 total poles and 4 protected poles. Its mechanism opens all poles simultaneously when the circuit breaker trips.

This configuration makes it possible to use a single device to protect circuits that require four-pole disconnection, simplifying integration into distribution boards.

C curve with magnetic tripping between 160 and 320 amps

The miniature circuit breaker features a C tripping curve. In this type of automatic circuit breaker, magnetic tripping in the event of short circuits occurs between 5 and 10 times the rated current.

For this 32-amp reference, Legrand specifies a magnetic tripping threshold between 160 and 320 amps. This feature allows certain temporary current surges to be tolerated without losing fast response to a short circuit.

6 kA breaking capacity according to EN 60898-1

According to EN 60898-1, the Legrand DX³ 407931 has a rated breaking capacity of 6 kA at 400 volts.

This value expresses the breaker’s ability to interrupt a short-circuit current under the test conditions established for circuit breakers intended for residential installations and similar applications.

10 kA breaking capacity according to IEC 60947-2

According to IEC 60947-2, the device’s ultimate breaking capacity reaches 10 kA at 400 volts. At 230 volts, Legrand specifies an ultimate breaking capacity of 25 kA.

For this reason, the commercial designation 6/10 kA corresponds to values obtained according to different standards and test conditions.

Energy limiting class 3

The miniature circuit breaker has an energy limiting class 3. This feature indicates its ability to limit the energy flowing through the circuit during certain short-circuit situations.

Limitation helps reduce the thermal and electrodynamic stresses that may occur on conductors and other installation components during a high overcurrent.

Rated voltage of 400 volts

The Legrand DX³ 407931 is designed to operate at a rated voltage of 400 volts AC and supports a frequency range of 50 to 60 Hz.

Its rated insulation voltage is 500 volts and its impulse withstand voltage reaches 4 kV.

DIN rail mounting in 4 modules

The automatic circuit breaker is designed for DIN rail mounting and occupies a width equivalent to 4 modules, allowing it to be installed alongside residual current devices, contactors and other modular devices inside the electrical panel.

The installation depth specified by Legrand is 44 mm.

Dimensions of the Legrand 407931

• Width: 70.8 mm.
• Height: 94.8 mm.
• Depth: 77.8 mm.
• Installation depth: 44 mm.
• Module width: 4 modules.

These dimensions make it possible to determine precisely the space required to install the miniature circuit breaker inside the electrical panel.

Top or bottom supply

The Legrand 407931 can be supplied from either the top or the bottom, providing flexibility during panel design and wiring.

Legrand allows supply via copper cable, top or bottom pin comb busbar, bottom fork comb busbar and compatible HX³ plug-in distribution systems from the top.

Terminals for rigid and flexible conductors

The miniature circuit breaker includes screw terminals and accepts different conductor cross-sections:

• Flexible or stranded conductor: between 1.5 and 25 mm².
• Rigid conductor: between 1.5 and 35 mm².

This connection capacity makes it easy to adapt to different panel configurations and cable sizes.

IP20 and IK02 protection

The breaker has an IP20 protection rating, with a design protected against accidental finger contact when the device is correctly installed.

Its mechanical impact resistance is IK02.

Designed for a wide temperature range

The Legrand DX³ 407931 can operate at an ambient temperature between -25 and 70 degrees Celsius. For storage, the manufacturer specifies a range between -40 and 70 degrees Celsius.

The device has a pollution degree 2, according to its technical characteristics.

Compatible with DX³ auxiliaries

The miniature circuit breaker can be fitted with compatible auxiliary devices from the Legrand DX³ range. This makes it possible to add control, signalling or remote tripping functions depending on project requirements.

Legrand also provides compatibility with accessories and blocks to expand the configuration possibilities of the electrical panel.

Easy circuit identification

The front includes a label holder that allows the protected circuit to be identified. This feature makes commissioning, maintenance and line identification easier in panels with numerous devices.

Technical features of the Legrand 407931

• Brand: Legrand.
• Range: DX³.
• Reference: 407931.
• EAN: 3245064079310.
• Product type: thermal-magnetic circuit breaker.
• Number of poles: 4.
• Number of protected poles: 4.
• Rated current: 32 amps.
• Tripping curve: C.
• Magnetic threshold: between 160 and 320 amps.
• Rated voltage: 400 volts AC.
• Frequency: between 50 and 60 Hz.
• Breaking capacity according to EN 60898-1 at 400 volts: 6 kA.
• Ultimate breaking capacity according to IEC 60947-2 at 400 volts: 10 kA.
• Ultimate breaking capacity 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.
• Mounting: DIN rail.
• Number of modules: 4.
• Width: 70.8 mm.
• Height: 94.8 mm.
• Depth: 77.8 mm.
• Installation depth: 44 mm.
• Protection rating: IP20.
• Impact resistance: IK02.
• Flexible or stranded 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: RAL 7035 grey.
• Label holder: yes.
• Compatible with auxiliary devices: yes.

Four-pole protection for electrical panels

The Legrand DX³ 407931 combines a 32-amp rated current, C curve, 4-pole protection and 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 mounting, top or bottom supply option, wide connection range and compatibility with DX³ auxiliaries make it easy to incorporate into electrical panels that require protection against overloads and short circuits.