RCCB for main distribution boards
The Siemens 5SV3648-6 is a 4-pole residual current circuit breaker (RCCB) with Type A sensitivity, rated at 100 A and 300 mA trip threshold for 400 V AC networks. Type A detection covers sinusoidal AC faults plus pulsating DC fault currents — the standard requirement for circuits with single-phase rectifiers, switched-mode power supplies, or electronic loads. At 100 A it serves as the main incoming protection or a feeder RCCB in a three-phase distribution board, not a final-subcircuit device.