The Siemens 5SY5215-7KK11 is a 2-pole C-curve miniature circuit breaker from the SENTRON family, rated 1.6 A at AC and 440 V DC with a 10 kA breaking capacity per EN 60898 (AC) and EN 60898-2 (DC). Rated for universal current (AC/DC) with a note: AC supply can land on either pole, but DC polarity must be observed — the marked line/load orientation matters on DC circuits. The 10 kA interrupting rating at 400 V AC and 440 V DC covers most industrial panel fault levels; if your SCCR study calls for 25 kA, step up to the 5SY6 series.
Occupies 2 modular width units (36 mm) on a DIN rail, depth 76 mm, height 90 mm — standard 1-pole-per-18 mm footprint, so it drops into any 35 mm rail enclosure without adapters. Mounting position any; fastening via the quick-assembly system (snap-on). Combined terminal top and bottom means the same cage clamp accepts both incoming and outgoing conductors — no separate feed-through lug needed.
Thermal derating — the real ampacity
Rated 1.6 A at 35 °C ambient, but the continuous current drops as the panel heats: 1.52 A at 40 °C, 1.48 A at 45 °C, 1.44 A at 50 °C, 1.4 A at 55 °C, and 1.36 A at 60 °C. If this breaker sits next to high-dissipation drives or transformers in a sealed cabinet, size the load at the 60 °C figure (1.36 A) — the nameplate 1.6 A is only valid in a cool 35 °C environment. Operating range -40 to 75 °C, pollution degree 3, overvoltage category III — it lives in the main distribution panel, not a clean room.