The Siemens 5SM3322-4KK14 is a 2-pole SENTRON 5SM3 series RCCB rated 25 A at 230 V AC, with a 30 mA trip threshold and Type B+ fault current detection. It is short-time delayed, withstanding surge currents up to 3 kA without nuisance tripping.
Mounting and integration
Snap-on DIN rail (REG) mounting, 4 width units (72 mm wide), 70 mm deep, 90 mm tall. IP20 with the distribution board installed and conductors connected. Mounting position is any — no derating required for horizontal or inverted orientation. The supply can enter from top or bottom; the SIGRES function (test/status) remains active even when switched off if fed from the bottom.
Thermal derating
Full 25 A rating holds at 40 °C and 45 °C. Derate linearly above that: 23.5 A at 50 °C, 22 A at 55 °C, 20.5 A at 60 °C, 19 A at 65 °C, 17.5 A at 70 °C. Ambient operating range is -25 °C to 45 °C; storage range is -40 °C to 75 °C.