Siemens SENTRON 5SY7313-8CC — 3-pole D-curve MCB, 13 A, 25 kA
It is part of the 5SY7CC design series, built for mechanical engineering and industrial panel applications where high inrush currents — motor starts, transformer energization, or welding loads — demand a D-curve to avoid nuisance trips. The 25 kA breaking capacity per IEC 60947-2 means it can safely interrupt a fault up to that level without cascading upstream; the 5 kA rating per UL 1077 and CSA C22.2 No. 235 covers North American branch-circuit installations. The 54 mm width (3 width units) and 90 mm height fit standard SENTRON enclosure layouts. Terminals accept solid or stranded conductors from 0.75 to 35 mm²; tightening torque is 2.5 to 3.5 N·m. The combined terminal design at both top and bottom simplifies busbar and cable routing.
D-curve selectivity and coordination
The D-curve (tripping characteristic class D) is the key differentiator from the more common B- or C-curve MCBs in the SENTRON family. Where a C-curve trips at 5–10× rated current, the D-curve allows 10–20× In — typically 130 to 260 A instantaneous trip for this 13 A unit. That headroom is essential when the breaker feeds a motor starter, a transformer primary, or a bank of power supplies that draw a short-duration inrush well above the running load. The trade-off is less protection for long, low-overload events; coordination with downstream overload relays or fuses is the normal practice. Compared to a C-curve sibling like the 5SY7210-7CC (10 A, C-curve), the 5SY7313-8CC carries a higher continuous rating and a wider instantaneous band. The 5SY3132-6 (a 3-pole C-curve 32 A unit) would not be a drop-in substitute — different curve, different rating, and the 5SY7CC design series uses a different terminal architecture. If your BOM specifies a 13 A D-curve, the 5SY7313-8CC is the correct SENTRON order code; no parametric cross within the same footprint exists.
Panel integration
Any mounting position is permitted. The combined terminal at top and bottom accepts solid or stranded copper up to 35 mm²; torque to 2.5–3.5 N·m. Sealable cover available for tamper-proof installations. Halogen-free and silicon-free housing suits clean-room or food-industry enclosures where outgassing is a concern.