32 A C-curve MCB for panel builders
The Siemens SENTRON 5SY7232-7CC is a 2-pole miniature circuit breaker rated 32 A with a C-curve tripping characteristic, meaning it handles moderate inrush currents from motor and transformer loads without nuisance tripping while still clearing short circuits fast. Breaking capacity sits at 25 kA per IEC 60947-2 at 400 V AC — enough headroom for most industrial distribution boards fed by a standard transformer. For UL 1077 and CSA C22.2 No.235 installations, the rating is 5 kA, so verify the available fault current if the panel is destined for a North American site.
What the ratings mean for fit
The 25 kA breaking capacity at 400 V AC per IEC 60947-2 is the figure that governs selectivity in European-style distribution — it tells you this breaker can safely interrupt a fault up to that level without the upstream device needing to clear it first. That 25 kA rating is the IEC service short-circuit capacity (Ics), not just the ultimate (Icu), which means it can be reclosed after a fault at that level. The UL 1077 supplementary-protector rating of 5 kA is a different standard — this is not a UL 489 listed branch-circuit breaker, so it goes in control panels, not as a service entrance device. The C-curve (tripping between 5 and 10 times rated current) suits mixed loads with some motor starting or transformer inrush — think conveyor drives, small pumps, or control transformers in a machine panel. If the load is purely resistive (heaters, lighting), a B-curve would give faster fault clearance, but the C-curve is the standard choice for general industrial use where you need to ride through brief inrush. Temperature range spans -40 to 75 °C, which covers unheated electrical rooms and outdoor enclosures in most climates. The humidity derating curve (max 95% RH at 55 °C, dropping to 35% at 75 °C) means you need to consider condensation in sealed enclosures — the breaker itself is IP20 with connected conductors, so it's not sealed against moisture ingress. Pollution degree 3 and overvoltage category III confirm it's rated for the conductive-dust and transient environment typical of industrial control panels.
Mounting and panel integration
Snaps onto DIN rail via the quick-assembly system — 2 modular width units (36 mm wide) with a 70 mm installation depth and 76 mm overall depth. Any mounting position works, and the combined terminal top and bottom accept conductors from either direction, which simplifies busbar and ring-main wiring in a crowded enclosure. The sealable feature lets you lock the toggle position to prevent unauthorized reset after a trip — useful on a line where only maintenance should re-energize a circuit.