Blog

Les normes essentielles à connaître : pourquoi les disjoncteurs différentiels de type B sont indispensables pour certaines applications industrielles

20 novembre 2025

Type B RCCBs are essential because they detect smooth DC fault currents that standard devices cannot see. When power electronics create DC leakage, Type AC and Type A RCCBs get blinded and fail to trip.Type B units use specialized detection technology that works across all fault current types. What is a Type B RCCB? A Type B RCCB is a residual current circuit breaker that detects AC, pulsating DC, and smooth DC fault currents. Type AC devices only detect alternating currents. Type A devices handle AC and pulsating DC. Type B is the only option that detects smooth DC currents from power electronics. Type B RCCBs use flux-gate detection technology instead of the standard core transformer design. This technology prevents magnetic saturation that blinds other RCCB types. The device maintains sensitivity across all fault current waveforms including high-frequency AC components and smooth DC currents. Comparing RCCB Types RCCB Type Detects AC Currents Detects Pulsating DC Detects Smooth DC Common Applications Type AC Yes No No Basic lighting, standard outlets Type A Yes Yes No Residential appliances, computers, LED lights Type B Yes Yes Yes VFDs, EV charging, solar systems, industrial equipment The RCCB Type A vs Type B difference comes down to smooth DC fault detection. Why Standard RCCBs Fail with Power Electronics Standard RCCBs use a core transformer that monitors current balance between live and neutral wires.Normal operation keeps these currents equal with no net magnetic field. Faults create imbalances that generate a magnetic field in the transformer core. When the field reaches a […]