What this MCB is and what it does
The Siemens 5SL3232-7MB is a SENTRON miniature circuit breaker (MCB) — a 2-pole, C-curve device rated at 32 A continuous current at 30 °C, with a breaking capacity of 4.5 kA per EN 60898 at 400 V AC. The C-curve means it trips between 5 and 10 times rated current, so it handles moderate inrush from motor starters or capacitor banks without nuisance tripping, while still clearing a hard short. For a 32 A feed protecting a general-purpose sub-distribution board or a fixed-load circuit in a residential or light commercial panel, this is the standard choice.
Panel fit and integration
The 5SL3232-7MB occupies 2 modular width units (36 mm) on a DIN rail, with a depth of 76 mm and an installation depth of 70 mm behind the panel face. It mounts in any position, which helps when the enclosure is tight on vertical clearance. IP20 with connected conductors is the standard for a panel-mounted MCB — no special washdown rating, so it stays inside the cabinet. The 2-pole design switches both phase and neutral, which is required for single-phase final sub-circuits in many national wiring rules.
What the ratings mean for your circuit
The 4.5 kA breaking capacity at 400 V AC per EN 60898 is the standard rating for this class — it is the maximum prospective short-circuit current the MCB can safely interrupt at the rated voltage. For a domestic or light commercial panel with a typical upstream transformer impedance, this is adequate. The 32 A rating at 30 °C is the continuous current; no derating curve is provided in the evidence, but for higher ambient temperatures inside a sealed enclosure, expect to apply a conventional derating factor. The mechanical service life of 10 000 switching cycles is typical for a panel circuit breaker — it is designed for occasional manual isolation, not daily load switching.