The Siemens SENTRON 5SU9356-1CN32 is a 2-pole RCBO — a residual-current-operated circuit breaker that combines overcurrent protection and earth-leakage detection in one 36 mm-wide module. It's rated 32 A at AC with a 30 mA residual trip and a C-curve tripping characteristic, so it handles motor and lighting inrush without nuisance trips while catching ground faults down to 30 mA. Breaking capacity is 6 kA per both EN 60898 and IEC 60947-2, which covers most commercial and light industrial panelboards. The Type AC residual-current sensing means it detects sinusoidal AC fault currents only — standard for general-purpose socket circuits and lighting where no pulsed DC or variable-speed-drive leakage is present. If your line has VFDs or switching power supplies, you'd need a Type A or F device instead.
Mounts on DIN rail — 2 modular width units (36 mm) — and the supply can enter from either top or bottom, which saves time when retrofitting an existing panel where the busbar arrangement is already set. Installation depth is 70 mm, overall depth 77 mm. The IP20 rating applies once the distribution board is enclosed and conductors are connected. Temperature derating is published: full 32 A at 30 °C, drops to 29.1 A at 40 °C, 27.8 A at 45 °C, 26.6 A at 50 °C, and 25 A at 55 °C. If this breaker sits in a hot cabinet or near other heat sources, use the 40 °C or 50 °C figure for your load calculation.