The Siemens SENTRON 5SM3626-4KK14 is a 2-pole residual current circuit breaker (RCCB) rated 63 A at 40 °C and 230 V AC, with a B+ fault current type and short-time delayed switching function. The 63 A rating at 40 °C is the continuous current it carries in a panel at that ambient — at 70 °C it still holds 50.4 A, so the thermal derating curve is real and worth checking if your enclosure runs hot near the kiln or furnace line. The B+ type detects AC, pulsating DC, smooth DC, and high-frequency fault currents up to 1 kHz, which covers variable-speed drive leakage and modern power supply earth faults that a standard AC type would miss. The short-time delayed design (S-type) means it withstands transient leakage pulses up to 3 kA surge current without tripping, giving selectivity with downstream instantaneous RCCBs — essential for a distribution board feeding multiple sub-circuits. IP20 with conductors connected, finger and back-of-hand safe per the protection class.
Integration and mounting notes
Mounting position is any orientation. The supply cord can enter from the top or bottom — bottom entry also powers the SIGRES function in the switched-off state. Installation depth is 70 mm, matching the device depth. The 4 width units (72 mm) occupy four 18 mm module spaces in a distribution board. Silicon-free construction, suitable for environments where silicone outgassing could contaminate contacts or optics.
Thermal derating across ambient temperature
Rated current is 63 A at both 40 °C and 45 °C ambient. At 50 °C it derates to 60.5 A, at 55 °C to 58 A, at 60 °C to 55.4 A, at 65 °C to 52.9 A, and at 70 °C to 50.4 A.