What it is and what it does
The Siemens 5SY5150-7CC is a 1-pole C-curve miniature circuit breaker (MCB) from the SENTRON family, designed for DC branch-circuit protection in industrial control panels and machinery. It carries a 50 A rating at 35 °C, derated to 46.6 A at 40 °C and 42.9 A at 50 °C, so the installer needs to account for enclosure ambient when sizing the load. The C-curve characteristic trips between 5× and 10× rated current, which suits moderate inrush loads like small motors, transformers, and capacitor banks — common in machine-tool and conveyor panels.
DC breaking capacity and fit
Rated 10 kA at 220 V DC (per IEC 60947-2), this MCB can safely interrupt fault currents up to that level on a DC bus. The operating voltage maxes at 250 V DC, so it covers common 220 VDC control circuits and battery-backed supplies. The 18 mm width (1 modular unit) means it snaps into a standard DIN rail without stealing extra space — panel fill factor stays tight.
Integration and compliance
Mounts in any position on the DIN rail, with a quick-assembly fastening system. Depth is 76 mm (installation depth 70 mm), so it clears most standard enclosures. Rated IP20 with connected conductors — fine for enclosed panels; not for wet washdown zones. Sealable, halogen-free, and silicon-free, which matters for clean-room or food-grade installations where outgassing or tamper evidence is tracked. Overvoltage category III and pollution degree 3, meaning it's rated for fixed-installation mains supply in industrial environments with conductive dust or humidity. Combined top and bottom terminals simplify daisy-chain wiring.