What this RCCB is and what the ratings mean
The Siemens 5SM3652-6 is a SENTRON residual-current circuit breaker (RCCB) — 4-pole, Type A instantaneous trip, rated 25 A at 40 °C and 300 mA residual current. The 10 kA short-circuit current rating (SCCR) at 500 V AC means it can safely interrupt fault currents up to that level without upstream damage, which is the figure you need for panel SCCR coordination. Type A detection handles sinusoidal AC and pulsating DC fault currents — the common mix in single-phase rectifier loads like switched-mode supplies and VFD front ends. The 300 mA trip threshold is typical for general distribution protection rather than personnel shock protection (which would be 30 mA); this is sized for equipment and fire-prevention protection on submain or feeder circuits.
DIN-rail fit and panel integration
Mounts on standard DIN rail (REG), 4 width units (36 mm wide), 70 mm depth. Installation depth matches the 70 mm dimension — verify your enclosure depth clears the body with conductors dressed. IP20 rating applies when installed in a distribution board with connected conductors; not rated for washdown or outdoor exposure without an enclosure. Any mounting position permitted. Supply connection at top or bottom.
Thermal derating and operating range
Rated 25 A at 40 °C and 45 °C; derates to 24 A at 50 °C, 23 A at 55 °C, 22 A at 60 °C, 21 A at 65 °C, 20 A at 70 °C. Operating ambient -25 °C to +45 °C; storage -40 °C to +75 °C. The derating curve is the selection gate for panels running warm — if your enclosure ambient sits at 60 °C, the continuous load limit drops to 22 A.