The Siemens 5SV3646-4KK14 is a 4-pole residual current circuit breaker (RCCB) from the SENTRON family, rated 63 A at 400 V AC with a 300 mA trip threshold and a Type B+ characteristic. The Type B+ designation means it detects smooth DC residual currents, AC pulsating currents, and high-frequency AC components — the full spectrum you'd expect from variable-speed drives, UPS systems, and PV inverters. The 300 mA sensitivity is not for personal shock protection (that's 30 mA); it's sized for equipment protection and fire prevention on circuits where leakage from power electronics would nuisance-trip a standard Type A device.
Snaps onto DIN rail (REG) in any mounting position — no gravity-dependent orientation. The 4-pole body occupies 4 modular width units at 60 mm grid spacing, so it fills 72 mm of rail width.
What the short-time delay buys you
The short-time delayed switching function means this RCCB tolerates brief surge currents without tripping — useful on circuits with capacitor banks, motor inrush, or transient earth faults from switching events. It's not a selectivity device per se (that's the SENTRON selective RCCB range), but the delay prevents nuisance tripping on circuits where a standard instant-trip RCCB would drop out on a harmless transient. The mechanical service life of 10 000 operating cycles is typical for a switch-disconnector in panel duty; it's not a daily-operating contactor, but it handles periodic isolation and test cycles without issue.
Silicon-free construction matters for automotive or electronics manufacturing environments where silicone outgassing can contaminate sensitive contacts or optics.