What it is and what it does
The Siemens 5SY7306-7CC is a SENTRON miniature circuit breaker (MCB) with a C tripping characteristic, 3 poles, and a rated current of 6 A at 35 °C. It protects branch circuits against overload and short circuit in final distribution boards and industrial control panels. The C-curve means it trips between 5 and 10 times rated current — suited for circuits with moderate inrush, like motor starters or small transformers.
Key ratings and what they mean for fit
Breaking capacity is 30 kA according to IEC 60947-2 — that's the maximum fault current it can safely interrupt at 440 V AC multi-phase without welding contacts or rupturing. For a panel with a high available fault current, this MCB holds its own without needing a current-limiting upstream device. Rated current derates with ambient temperature: 6 A at 35 °C, 5.67 A at 40 °C, 5.5 A at 45 °C, 5.32 A at 50 °C, and 5.13 A at 55 °C. If the panel runs hot, size the load to the derated figure, not the 35 °C number. Pollution degree 3 and overvoltage category III mean it's rated for the industrial environment — conductive pollution or dry non-conductive pollution that becomes conductive due to condensation is expected. That's typical for control cabinets near machinery.
Mounting and integration
Snaps onto DIN rail via the quick assembly system. Occupies 3 modular width units (54 mm) and installs at any mounting position. Combined terminals top and bottom accept both cable and busbar — no separate feed-through lug needed. Installation depth is 70 mm; overall depth is 76 mm.