The Siemens 5SM3344-6 is a SENTRON residual current circuit breaker (RCCB) — a 4-pole, Type A device rated for 40 A at 40 °C with a 30 mA trip threshold and a 400 V AC supply. That makes it the baseline for most commercial and light-industrial panels today; you'd step up to Type B only if three-phase rectifiers or frequency converters are in the circuit.
The 30 mA trip threshold is the standard for personal shock protection in most IEC-governed installations — it's the level that protects against ventricular fibrillation under dry-body conditions. The 40 A continuous rating holds at 40 °C ambient; at 45 °C it still carries 40 A, then derates to 38.4 A at 50 °C, 36.8 A at 55 °C, and steps down to 32 A at 70 °C. If your panel runs hot, use the 50 °C or 60 °C column for sizing. The let-through energy is rated at 70 000 A²·s, and the surge current withstand is 1 kA (8/20 µs waveform).
Panel integration
IP20 with connected conductors in an installed distribution board — standard for enclosed panels, not for open washdown areas. Mounting position is unrestricted, which simplifies layout in tight enclosures. Silicon-free construction, so it's safe for use in automotive paint-shop or coating environments where silicone outgassing can cause adhesion failures.