What this 13 A D-curve MCB means on the line
The Siemens SENTRON 5SY4113-8CC is a 1-pole miniature circuit breaker rated 13 A with a D tripping characteristic, meaning it tolerates the high inrush currents typical of motor starters, transformers, and welding equipment without nuisance tripping — the magnetic trip fires between 10× and 20× rated current. On a 400 V AC supply it delivers 10 kA breaking capacity per EN 60898, enough for most industrial sub-distribution boards; if you are wiring to UL 1077 standards the SCCR drops to 5 kA, so verify your available fault current before committing the BOM line.
Panel fit and wiring constraints
At 18 mm width (1 width unit) and 76 mm depth, it fits tightly into existing SENTRON sub-distribution boards without crowding adjacent breakers. The combined terminals top and bottom accept 0.75–35 mm² solid or stranded copper; tighten to 2.5–3.5 N·m with a Pozidriv screwdriver.
Miniature circuit breakers with a D curve are specified for circuits with high magnetizing inrush — motor starters, solenoid banks, small transformers, and DC power supplies. The 5SY4113-8CC is rated for mechanical engineering and industrial environments per the manufacturer's own suitability listing.