The Siemens 5SU1636-7FP32 is a 3-pole RCBO (residual current circuit breaker with overcurrent protection) from the SENTRON family, combining a 32 A thermal-magnetic MCB with a 300 mA residual-current device in one 54 mm wide, 3-module-width unit. The C-curve tripping characteristic means it handles inrush currents up to 5–10× rated current before the magnetic trip fires — typical for motor starters, contactor coils, and small transformer loads where you don't want nuisance trips on energisation. The 300 mA residual-current sensitivity (Type A) catches sinusoidal AC faults and pulsating DC faults up to 6 mA smooth DC, which covers most modern electronics and variable-speed drive leakage without being so sensitive that it trips on normal cable capacitance.
Thermal derating — the real-world current rating
The 32 A rating holds only at 30 °C ambient. At 40 °C — common inside a loaded distribution board — the continuous rating drops to 30.8 A; at 50 °C it's 29.5 A; at 60 °C it's 28.8 A. The RCBO mounts in any position, and the supply cord can enter from top or bottom, which gives flexibility in a crowded enclosure. Installation depth is 70 mm — factor that into gland-plate clearance if you're using deep cable entries.
Environmental and installation constraints
The housing is rated IP20 only when installed in a distribution board with connected conductors — this is a panel-internal device, not a field-mounted unit. Insulation voltage is 500 V, so it's fine on 230/400 V TN systems.