The Siemens 5SU9356-7CN32 is a 1P+N RCBO rated at Icn 6 kA, combining overcurrent and residual current protection in a single module. It carries a Type A residual-current sensitivity of 30 mA, a C-characteristic for the overcurrent trip curve, and a rated current In of 32 A at Un AC 230 V.
The 30 mA Type A RCD element detects sinusoidal AC and pulsating DC fault currents, covering the common fault modes in residential and light commercial final circuits. The C-curve (5–10× In) handles moderate inrush from motorized or capacitive loads without nuisance tripping. Rated Icn 6 kA at 230 V AC means this device safely interrupts short-circuit currents up to 6 kA without external backup protection, suitable for domestic distribution boards with typical prospective fault levels below that threshold. The 1P+N form factor switches the line conductor only; the neutral is switched internally for isolation but not protected against overcurrent. This is standard for single-phase final circuits in TN or TT systems where the neutral is not fused.