The Siemens 5SV3346-6LA is a SENTRON residual current circuit breaker (RCCB) — 4 poles, Type A, rated 63 A at 50 Hz, with a 30 mA trip threshold and instantaneous response.
Mounting position doesn't matter — any orientation works. Feeds can land top or bottom, which saves time when you're wiring a crowded enclosure and the gland plate is already full. The silicon-free construction matters if you're putting it in a panel near potting or coating processes where silicone outgassing can cause contact issues.
Rated current holds at 63 A from 40 °C up to 55 °C; it starts to derate above that — 57.35 A at 65 °C, 48.8 A at 70 °C. The let-through energy (I²t) is rated at 110,000 A²·s, and surge current resistance is 1 kA. Overvoltage category III means it's suited for fixed-installation distribution boards, not just downstream equipment.