The Siemens SENTRON 5SY5404-7CC is a 4-pole miniature circuit breaker rated 4 A with a C tripping characteristic, designed specifically for DC circuits up to 880 V. It carries a 10 kA breaking capacity per IEC 60947-2 at 880 V DC, making it suitable for protecting DC distribution panels, photovoltaic combiners, and industrial DC bus systems where the fault current can reach that level.
The C-curve means the magnetic trip threshold is 5 to 10 times rated current — 20 to 40 A — so it handles moderate inrush from DC loads like contactor coils or power supplies without nuisance tripping, while still clearing short circuits fast enough for the downstream equipment. The 4-pole design switches all poles simultaneously, but note that neutral conductor switching is not provided — the breaker is intended for ungrounded DC systems where all poles are line conductors. Polarity must be observed when connecting the supply.
The 5SY5404-7CC snaps onto a standard DIN rail via the quick assembly system and occupies 4 modular width units (72 mm).
Halogen-free and silicon-free construction reduces corrosive off-gassing in enclosed panels. The breaker is sealable for tamper-proof applications. Degree of pollution 2 and overvoltage category II cover standard industrial environments. Vibration resistance per IEC 60068-2-6 is ±1 mm at 5 to 25 Hz and 50 m/s² at 25 to 150 Hz — adequate for most machine-mounted panels.