DX3 Legrand Differential Circuit Breakers

What is an differential circuit breaker?

We can't stress this enough: the differential circuit breaker is an essential element in protecting your electrical installation against current leaks to earth. It detects any anomalies and automatically cuts the circuit in the event of a fault. It also prevents any risk of electrocution. In short, they are an essential part of any modern electrical installation. They should be installed in addition to standard circuit breakers, which protect against short circuits and overloads.
How do they work? The differential circuit breaker continuously measures the difference between the current entering and leaving the circuit. If this difference exceeds a predefined threshold (generally 30mA for domestic installations), the circuit-breaker trips instantly and cuts off the power supply.

Why use a DX3 differential circuit breaker?

Optimum performance, compliance with the strictest standards, robustness and advanced technology... when you choose DX3 differential circuit breakers , you can be sure of reliable protection for your electrical circuit. They meet the requirements of both professionals and private customers who are concerned about the quality of their installations.
The circuit-breakers in the DX3 range are designed to withstand intensive conditions of use and offer great stability of performance over time. What's more, their compact design makes them easy to integrate into switchboards, even in the most confined spaces.

How do I install a Legrand differential circuit breaker?

Please note that the installation of an differential circuit breaker must be carried out by a qualified professional to guarantee the safety and compliance of the installation.

• Preparation: Switch off the mains supply and gather the necessary tools (screwdriver, pliers, voltage tester).
• Installation: Attach the circuit breaker to the electrical panel by snapping it onto the DIN rail. Then connect the cables according to the diagram provided, scrupulously observing the colour codes and recommended cable cross-sections.
• Check: Make sure all connections are tight, switch the power back on and test the circuit breaker using the built-in test button.

What are the different types of circuit-breakers and differential switches?

There are several types of differential circuit breaker:

• AC type : Detects alternating current leaks. Ideal for standard domestic circuits, offering effective basic protection for most standard household appliances.
• Type A : Detects AC and pulsating DC leakage. Recommended for modern domestic appliances such as washing machines, induction hobs, or appliances with variable speed drives.
• Type F: Detects high-frequency current leaks. Suitable for modern electronics and sensitive equipment such as computers, high-end audio-visual systems, or home medical equipment.
• Type B: Detects direct and alternating current leaks. Used for photovoltaic installations, electric vehicle charging stations, and specific industrial equipment requiring increased protection against all types of leakage current.

One-Elec's catalogue includes two-pole models (generally used for single-phase circuits in homes) and four-pole models (for three-phase installations, common in industrial or commercial environments), type AC, A, F or B. Our products are also available in a range of current ratings (from 25A to 63A) and sensitivities (30mA) for optimum protection.

How do I choose the right DX3 circuit breaker?

To choose the right differential circuit breaker, pay attention to several factors:

• Sensitivity : Generally 30mA for personal protection, but higher sensitivities (300mA, 500mA) can be used to protect property against fire.
• Rating: This must be adapted to the maximum current of the protected circuit. For example, a 40A circuit-breaker for a socket circuit, or a 63A circuit-breaker for a general feeder.
• Tripping curves : B for a long cable length, C for conventional switchgear, D for motor starting.
• Number of modules : DX3 differential circuit breakers are available in different widths, generally from 2 to 4 modules, to fit all electrical panels. The tripping curve: This determines how quickly the circuit-breaker reacts in the event of an overload or short-circuit.

How long does a differential circuit breaker last?

If properly maintained, your differential circuit breaker can last for several decades. To ensure that this is the case, however, we recommend that you check its operation regularly (ideally once a month) using the test button. This simple test ensures that the tripping mechanism is working properly.
In the event of malfunction or frequent nuisance tripping, replace the circuit-breaker immediately to maintain the safety of the installation. It is also advisable to have your electrical installation inspected by a professional every 10 years to ensure that it is compliant and safe.
Our online shop offers a complete selection of Legrand DX3 differential circuit breakers, available from stock and ready to ship. If you have any questions or doubts, our technician is at your disposal. Now is the time to find the differential circuit breaker best suited to your needs at a competitive price!