20 A C-curve MCB for panel protection
The Siemens 5SY6520-7CC is a SENTRON miniature circuit breaker rated 20 A at AC with a C tripping characteristic, configured as 2-pole (1P+N). The C-curve means it trips at 5 to 10 times rated current — suited for mixed resistive and moderate inductive loads where inrush is present but not extreme, such as contactor coils, small motor circuits, or general distribution subfeeds in industrial panels. Breaking capacity is 6 kA per EN 60898 — adequate for most low-fault industrial and commercial sub-distribution boards where the prospective short-circuit current stays under that threshold. For UL 1077 / CSA C22.2 No. 235 recognition, the interrupting rating is 5 kA, so verify the available fault current if the panel carries a UL label.
Panel integration and environmental fit
Occupies 2 modular width units (36 mm) on a DIN rail, with a quick-assembly fastening system and any mounting position. Depth is 76 mm; installation depth 70 mm. The IP20 rating (with connected conductors) is standard for enclosed distribution boards — not for wet or washdown zones. Ambient operating range spans -40 °C to 75 °C, with derated current values above 40 °C: 18.8 A at 40 °C, 17.52 A at 50 °C, 16.84 A at 55 °C. Combined terminal top and bottom, touch protection, and pollution degree 3 (conductive pollution or dry non-conductive pollution that becomes conductive due to condensation — typical in industrial enclosures without climate control). Halogen-free and silicon-free construction matters for environments sensitive to outgassing, such as clean rooms or sealed control cabinets near sensitive electronics.