Siemens 5SY6315-8 — SENTRON 3-Pole D-Curve MCB, 1.6 A
The Siemens 5SY6315-8 is a 3-pole miniature circuit breaker from the SENTRON 5SY6 series, rated at 1.6 A with a D tripping characteristic. It is designed for 400 V AC systems and carries a breaking capacity of 6 kA per EN 60898 and 30 kA per IEC 60947-2, with a DC rating of 15 kA per IEC 60947-2 and 5 kA per UL 1077 / CSA C22.2 No. 235. The D curve means it tolerates high inrush currents — typically found in motor, transformer, or lighting ballast circuits — without nuisance tripping, while still providing short-circuit protection. This is a current-production part, sourced and quoted to order against an RFQ through independent distribution.
What the Ratings Mean for Fit
The 1.6 A rating and D curve make this MCB a fit for protecting a single small motor or a group of inductive loads where the starting surge exceeds 10× the full-load current. The 6 kA breaking capacity under EN 60898 covers standard residential and light commercial panel duty; the 30 kA rating under IEC 60947-2 means it can be used in industrial distribution where fault currents are higher — a key distinction for panel builders specifying for a 400 V industrial supply with a transformer upstream. The 3-pole configuration interrupts all three phases simultaneously, which is standard for three-phase motor circuits. The 72 V DC maximum rating (per IEC 60947-2) also allows limited DC branch protection, though the primary application is AC. The terminal accepts solid or stranded conductors from 0.75 to 35 mm², with combined top and bottom terminals for easy daisy-chaining or feed-through wiring. The 54 mm width (3 width units) snaps onto a standard DIN rail via the quick assembly system. IP20 protection (with connected conductors) is typical for enclosed panel mounting — not for wet or dusty environments without an enclosure. The ambient temperature range of -25 to +55 °C covers most indoor industrial settings, with humidity limits specified up to 95% at 55 °C.
Compliance and Approvals
The 5SY6315-8 carries approvals per EN 60898, IEC 60947-2, and UL 1077 / CSA C22.2 No. 235, covering the major regulatory jurisdictions for industrial control panels. It is halogen-free and silicon-free, which matters for applications sensitive to outgassing (e.g., clean rooms, medical devices, or sealed enclosures). The touch-protection feature (fingertip-safe terminals) is standard for modern DIN-rail components. Overvoltage category III means it is rated for fixed installation downstream of the main distribution board, not for socket outlets.