Miniature Circuit Breaker for Motor and Transformer Circuits
Siemens SENTRON 5SJ4320-8HG41 is a 3-pole D-curve miniature circuit breaker rated 10 kA and 15 kA breaking capacity, 400 V AC, 60 V DC. Sealable, halogen-free, silicon-free for confined panels.
How the D-Curve Differs from the 5SY Series
The 5SY4 series (e.g. 5SY4350-8) shares the same 3-module-wide footprint, 54 mm width, and DIN-rail mounting as the 5SJ4320-8HG41. The critical difference is the trip curve: the 5SJ carries a D-characteristic, which permits 10–20× rated current for brief inrush, while a comparable 5SY part may use B or C curve. If your panel was specified around a 5SY4350-8, confirm the required curve before drop-in substitution — the mechanical fit is identical, but the protection response is not.
Installation depth is 70 mm; width is 3 modular units (54 mm). Sealable for positive lockout/tagout – important for maintenance isolation. IP20 with conductors connected, IP40 at the handle. Operating temperature range -40 to 75 °C, suitable for unheated enclosures. Terminal tightening torque specified at 3.5 Nm for Cu conductors.