The Siemens 5SU1356-7KV25 is a combined residual-current device and miniature circuit breaker (FI/LS-protector) in a single 1+N-pole module. The 70 mm depth fits standard DIN-rail distribution boards.
Type A detection covers both sinusoidal AC residual currents and pulsating DC — the common waveform from rectifiers, switched-mode supplies, and variable-speed drives. The C-curve 25 A overcurrent characteristic handles motor-starting inrush and moderate inductive loads without nuisance tripping.
Deployment context
Snap-on DIN-rail mounting for panel integration. The 1+N-pole format (switched phase, switched neutral) is common in single-phase final circuits where neutral isolation is required.