RCBO with Type A residual current and C-curve overcurrent
The Siemens 5SU9356-7CR32 is a 1P+N RCBO combining overcurrent protection (C-curve, 32 A rated current) with residual current detection (Type A, 30 mA sensitivity) in a single DIN-rail module. Its 6 kA rated breaking capacity (Icn) at 230 V AC is sized for final subcircuits in residential and light commercial distribution boards where the prospective fault current stays under that threshold.
What the ratings mean for panel fit
The C-curve characteristic means the magnetic trip operates at 5 to 10 times In (160–320 A) — suited for inductive loads like small motors or fluorescent lighting banks where inrush would nuisance-trip a B-curve. Type A residual current detection covers pulsating DC fault waveforms from single-phase rectifiers (switched-mode supplies, LED drivers, washing machine electronics), not just sinusoidal AC. The 30 mA sensitivity meets the 30 mA threshold for additional protection against direct contact per IEC 60364. The 1P+N form factor occupies a single modular DIN-rail width (18 mm per pole typical for Siemens 5SU9 series). Neutral switching is integral — the N pole opens and closes with the phase, which avoids a floating neutral on trip. Verify the neutral busbar arrangement in the distribution board: some older boards use a solid N bar that must be broken for this RCBO.