The Siemens 5SV3746-5 is a 4-pole Type B selective residual current circuit breaker (RCCB) from the SENTRON family, rated 63 A and 500 mA residual sensitivity on a 400 V AC supply. The selective design means it incorporates a short-time delay so that, in a fault, the downstream RCCB trips first — only if the fault persists does this unit clear, keeping upstream circuits live. That discrimination is essential in a multi-level distribution board where you want the nearest device to the fault to open, not the main incomer.
Type B detection covers AC, pulsating DC, and smooth DC residual currents up to 500 mA — the right choice for drives, UPS systems, and other loads that can generate DC fault currents a standard Type A RCCB would not see. Mounting position is unrestricted.
Type B selective RCCBs are specified in commercial and industrial distribution boards where the supply feeds equipment that can produce smooth DC fault currents — variable-frequency drives, UPS systems, EV chargers, and medical imaging equipment. The selective time delay avoids nuisance tripping from transient earth faults and coordinates with downstream RCCBs so only the faulted branch opens. The 63 A rating covers sub-distribution or feeder circuits in a 400 V TN or TT system.