Siemens 5SY8225-7 SENTRON MCB — 2-pole, 25 A, C-curve, 30 kA
The Siemens 5SY8225-7 is a 2-pole miniature circuit breaker from the SENTRON series, rated 25 A at 440 V AC with a C tripping characteristic. It delivers a 30 kA breaking capacity per IEC 60947-2, meaning it safely interrupts fault currents up to that level without upstream cascading — a key figure for panel SCCR coordination. The DC rating is 15 kA at 72 V, covering control-circuit protection in DC bus applications. The C-curve (tripping between 5 and 10 times rated current) suits moderate inrush loads like motor starters and small transformers — common in mechanical engineering and industrial panels. The 2-module width (36 mm) and 76 mm depth fit standard DIN-rail enclosures; the quick-assembly fastening system and any-position mounting simplify panel integration. Ambient temperature derating is published: at 50 °C the continuous rating drops to 24.38 A, at 55 °C to 23.72 A. The part is halogen-free and silicon-free, which matters for clean-room or semiconductor-fab environments where outgassing is a concern. IP20 with connected conductors is standard for enclosed panel mounting.
Compliance and approvals
The breaker carries IEC 60947-2 certification for the 30 kA breaking capacity, and is designed for overvoltage category III, pollution degree 3. The product designation per IEC 81346-2 and EN 61346-2 is letter F. Sealable terminals are standard, allowing lockout-tagout compliance.