The Siemens 5SU9353-7CR16 is a 1P+N RCBO combining overcurrent and residual current protection in a single DIN-rail module. It is rated for 16 A with a C-trip characteristic (magnetic release at 5–10× In) and a 30 mA Type A residual-current sensitivity, covering sinusoidal AC and pulsating DC fault currents up to 6 mA smooth DC. Breaking capacity is 4.5 kA at 230 V AC, which is the standard domestic and light-commercial fault level for this form factor.
The 30 mA residual-current threshold is the standard for personal protection against direct contact (IEC 60364-4-41). Type A detection catches the rectified fault currents common in modern electronics (switched-mode PSUs, variable-speed drives, washing machines). The C-curve at 16 A suits lighting, general sockets, and small motor loads where inrush is moderate — not for heavy starting currents that would need a D-curve.