The Siemens 5SY5410-7 is a 4-pole miniature circuit breaker from the SENTRON family, with a C-curve tripping characteristic rated at 10 A AC and a breaking capacity of 10 kA per IEC/EN 60898-2 and UL1077. The C-curve means it handles moderate inrush — typical for motor starters, lighting banks, and transformer primaries — without nuisance trips, while still clearing short circuits fast enough to protect downstream wiring. At 40 °C ambient the continuous rating derates to 9.39 A; at 60 °C it drops to 8.04 A, so if the panel runs hot, size up one step. The 4-pole design (4P) switches all three phases and the neutral, but the neutral pole is not switched — it's a solid neutral bar. That matches most European and North American distribution panels where the neutral is bonded to ground at the service entrance and should never be opened. The part is rated for universal current operation, meaning it handles both AC and DC fault clearing; the DC breaking capacity is also 10 kA per EN 60898-2. On DC circuits, watch polarity — the supply cord position is AC as required, but DC polarity must be observed.
The terminals are combined (top and bottom), accepting conductors from the same entry point — no separate neutral bar needed. Sealable with a lead seal if the inspector requires tamper evidence. Pollution degree 2 (normal industrial, non-condensing) and overvoltage category II (distribution board level).