Siemens 5SY4103-7 — SENTRON 1-pole MCB, C-curve, 10/35 kA
It carries a C tripping characteristic, meaning it is designed for moderate inrush currents — typical for motor control circuits, lighting banks, and general industrial loads where the start-up surge is higher than a resistive load but not extreme. Rated for 400 V AC (single- or multi-phase) and up to 72 V DC, it offers a breaking capacity of 10 kA per EN 60898-1 and 35 kA per IEC 60947-2 — the higher figure applies when the MCB is used in industrial distribution where fault currents can be severe. Under UL 1077 / CSA C22.2 No.235, the rating is 5 kA.
Width is 18 mm (one modular unit), depth 76 mm, height 90 mm. The neutral conductor is not switched (single-pole design). Sealable for lockout/tagout compliance.
Operating temperature range is -40 °C to 75 °C, with humidity derating: max 95% RH at 55 °C, 55% at 70 °C, 35% at 75 °C. Halogen-free and silicon-free construction. Energy limitation class 3. Approvals include IEC/EN 60898-1, IEC/EN 60947-2, and UL 1077 / CSA C22.2 No.235 — covering both IEC and North American standards. The dual rating means the same part can be specified for export panels or multi-standard projects without a separate UL version.