The Siemens 5SY1706-2 is a SENTRON device circuit breaker — a 1-pole unit with an integrated auxiliary switch (normally-open contact), rated 6 A with characteristic F1. The auxiliary NO contact gives you a local status signal without needing a separate auxiliary block, which saves a module width on the DIN rail.
Characteristic F1 is a fast-acting trip curve — it clears short-circuit faults in under one cycle at high overcurrents, but also holds through moderate inrush from capacitive or electronic loads better than a standard B-curve. This makes it a good fit for protecting control transformers, power supplies, and semiconductor circuits where the load draws a brief charging current at startup. The 6 A rating at 230 V AC (250 V max single-phase) and 60 V DC (72 V DC max) covers most 24 VDC control circuits and 120/230 VAC auxiliary loads in a panel. The 1-pole + auxiliary switch design (1P+AS) means the breaker itself occupies one 18 mm modular width on the DIN rail, and the built-in NO contact follows the main contacts — no extra wiring for a remote panel-indication lamp or PLC digital input. Mounting position is horizontal or vertical, and the IP20 finger-safe terminals accept standard screwdriver-terminated wiring.
Rated to IEC / DIN EN 60934 (equipment circuit breaker standard) and UL1077 (supplementary protector for North America).