Legrand 402037 RX3 Residual Current Device 40A 2-Pole 30mA Type A 230V AC 2 Modules

Electrical faults can strike without warning, leaving circuits vulnerable to leakage currents that standard breakers may miss. The Legrand 402037 RX3 residual current device (RCD) steps in as a critical safeguard, instantly disconnecting power when it detects harmful residual currents—protecting both people and equipment from the risks of electric shock and fire. This 2-pole, 40 A unit with a 30 mA sensitivity is engineered for residential and commercial installations where reliability is non-negotiable.

Who is it for

Electricians, panel builders, and facility managers who need a dependable Type A RCD for AC and pulsating DC fault currents. It fits perfectly in distribution boards where space is tight, thanks to its compact 2-module width, and is ideal for circuits supplying socket outlets, lighting, or appliances.

Main features

• Type A tripping: detects AC and pulsating DC residual currents, covering modern loads like washing machines and LED drivers.
• 40 A rated current and 30 mA sensitivity: balances high load capacity with personal protection against electric shock.
• 2-pole design for single-phase 230 V AC networks, with 6 kA short-circuit withstand rating.
• DIN rail mounting with screw terminals accepting rigid conductors up to 35 mm² and flexible up to 25 mm².
• Test button and clear ON/OFF indicator for quick verification and status checks.
• Meets IEC/EN 61008-1, with 10,000 electrical and 20,000 mechanical cycles for long service life.

Specifications

• Series: Legrand RX3
• Number of poles: 2
• Rated current (In): 40 A
• Rated residual operating current (IΔn): 30 mA
• RCD type: Type A
• Rated voltage (Un): 230 V AC
• Frequency: 50/60 Hz
• Mounting type: DIN rail
• Module width: 2 modules (35 mm)
• Rated short-circuit current (Icn): 6 kA
• Connection type: Screw terminals
• Terminal capacity (flexible): 1.5 to 25 mm²
• Terminal capacity (rigid): 1.5 to 35 mm²
• Degree of protection: IP20 (terminals), IP40 (front panel in enclosure)
• Operating temperature: -25°C to +60°C
• Standards: IEC/EN 61008-1
• Electrical endurance: 10,000 cycles
• Mechanical endurance: 20,000 cycles
• Features: Test button, ON/OFF position indicator

Tips

For optimal protection, pair this RCD with suitable miniature circuit breakers (MCBs) on the same DIN rail to guard against both overcurrent and earth leakage. Regularly press the test button (every 6 months) to ensure the device trips correctly and maintains its protective function.