Residual-current circuit breaker Legrand 2P 25A B 30mA type AC (model 410923)

Legrand residual-current and overcurrent device, 2-pole with 25 A rated current, B tripping characteristic and 30 mA residual current sensitivity (type AC). Designed to combine short-circuit and overload protection with earth-leakage detection in a single modular unit suitable for domestic and light-commercial electrical installations. The device interrupts supply when residual alternating current exceeds 30 mA or when overcurrent conditions occur according to the B characteristic curve, helping to meet safety requirements and reduce risk of electric shock and fire from insulation faults.

Advantages

This 2P unit integrates residual-current protection and overcurrent (MCB) functionality in one compact module compatible with standard DIN-rail mounting. The 25 A rating and B characteristic provide fast tripping on moderate short-circuits while maintaining discrimination for typical household and small-office circuits. Type AC sensitivity detects sinusoidal alternating leakage currents down to 30 mA, offering a balance between protection and practical nuisance tripping in conventional installations. The modular design simplifies wiring and saves space in distribution boards.

Suitable for

• Protection of lighting circuits and socket outlets in homes
• Overcurrent and earth-leakage protection in small commercial premises
• Branch circuits supplying appliances with standard AC leakage patterns

Key specifications

• Poles: 2-pole protection (single-phase circuits)
• Rated current: 25 A
• Tripping characteristic: B curve (standard thermal-magnetic response)
• Residual current sensitivity: 30 mA, Type AC (detects alternating sinusoidal leakage)
• Combined function: residual-current device with integrated overcurrent protection
• Mounting: DIN-rail compatible modular enclosure

How to use

Install the device in the consumer unit on a standard DIN rail, following local wiring regulations and ensuring the supply is isolated before work begins. Connect the line and neutral conductors to the designated terminals and ensure protective earth continuity in the distribution board. Verify correct polarity and tighten terminals to the manufacturer’s torque recommendations. After installation, test the residual-current function using an appropriate test procedure or test button where fitted and confirm the circuit breaker trips under fault conditions before returning the installation to service.

Usage recommendations

Use this unit where protection against AC sinusoidal earth leakage and overcurrent is required; ensure coordination with upstream and downstream protective devices and consider selective sensitivity or type upgrades (e.g., type A or type B devices) where non-sinusoidal leakage or electronic equipment is present. Periodic testing and inspection in line with applicable electrical safety standards is advised to maintain reliable protection.