The Siemens 5SY4232-7 is a 2-pole miniature circuit breaker from the SENTRON 5SY series, occupying 36 mm (2 modular width units) on a DIN rail. Breaking capacity is 10 kA per EN 60898-1 at 400 V AC, and 20 kA per IEC 60947-2 at the same voltage — the higher figure applies when the breaker is used as a distribution-level device under the industrial standard, giving selectivity headroom downstream. For DC circuits, it is rated 15 kA at 72 V maximum per IEC 60947-2, and 5 kA per UL 1077 / CSA C22.2 No.235.
Environmental and installation constraints
The breaker is rated for ambient temperatures from -40 °C to 75 °C, with humidity derating above 55 °C — at 70 °C the max relative humidity drops to 55%, and at the 75 °C ceiling it is 35%. This matters for sealed enclosures or panels near steam lines where condensation risk rises with temperature.