What this SENTRON MCB is and what it handles
The Siemens SENTRON 5SY5232-7CC11 is a 2-pole miniature circuit breaker rated 32 A with a C tripping characteristic, designed for universal current operation — it handles both 440 V DC and 400 V AC circuits.
Built for the route — railway and DC plant
This breaker is explicitly designed for railway applications, so it's built to handle the vibration, temperature swings, and DC bus voltages you find under the floor of a railcar or in a trackside cabinet. The 70 mm installation depth and 76 mm overall depth fit standard enclosures. Pay attention to polarity on DC: the spec calls out that the power supply position requires polarity consideration. On AC it doesn't matter, but on a DC circuit you need to wire it correctly. The breaker is sealable and touch-protected with IP20 when conductors are connected. No neutral switching on this 2-pole unit — it's a line-side breaker only.
This breaker carries the SENTRON brand and is classified under DIN EN 61346-2 and DIN EN 81346-2 as function code F. It's designed to IEC 60947-2 for DC breaking capacity. The surrounding temperature influence is specified: max 95% RH up to 55 °C, derating to max 55% RH at 70 °C and max 35% RH at 75 °C.