The Siemens 5SV3646-8LA is a SENTRON-series RCCB (residual current circuit breaker) designed for 4-pole, 63 A circuits with a 300 mA Type A selective trip characteristic. The 300 mA rating means it's intended for general fault protection where a higher threshold is acceptable — typically on feeder circuits or sub-distribution boards — and the selective (time-delayed) design coordinates with downstream 30 mA RCCBs so only the faulted branch trips, not the whole board. Type A detection covers sinusoidal AC and pulsating DC residual currents up to 6 mA smooth DC, which covers most modern electronic loads like VFDs, switched-mode PSUs, and single-phase rectifiers. The 5SV3646-8LA carries a 10 kA short-circuit current rating (SCCR) per IEC 61008-1, with a conditional rating of 0.8 kA under EN 60898. The I²t let-through is rated at 110,000 A²·s, which governs the energy the device passes during a fault — relevant for coordination studies. Thermal performance is flat-rated at 63 A from 40 °C through 60 °C ambient, then derates to 57.35 A at 65 °C and 48.8 A at 70 °C. This means in a warm panel (say 55 °C), the device still carries its full 63 A without derating — a useful margin for tightly packed enclosures.
Installation depth matches the body depth at 70 mm.