The Siemens 5SU1356-1DA32 is a combined residual-current and miniature circuit breaker (RCBO) — an FI/LS protector in Siemens' 5SU series. It integrates ground-fault and overcurrent protection into a single 1+N-pole unit, sized for a 32 A C-curve thermal-magnetic trip and a 30 mA Type AC residual-current trip. The pig-tail connection on the neutral side simplifies wiring in a standard DIN-rail enclosure, provided the installer observes the manufacturer's torque and strip-length specification.
The C-curve (32 A) means the magnetic trip operates between 5× and 10× rated current — 160 A to 320 A — so it tolerates the inrush of motor-driven loads like pumps or compressors without nuisance tripping, provided the branch circuit's starting surge stays within that band. For variable-speed drives, LED drivers, or any load with rectification, a Type A or Type B RCD would be required. The 6 kA breaking capacity (Icn) is the short-circuit rating per IEC 61009-1. If the supply transformer is close enough to push fault current above 6 kA, a limiting MCB or fuse upstream is necessary to keep the let-through energy within the RCBO's rating.
Deployment context
The 70 mm width and DIN-rail mounting profile mean it occupies a standard modular slot in a consumer unit or sub-distribution board. The pig-tail neutral connection requires landing the factory-attached lead on the neutral busbar.