The Siemens 5SU1356-7KV20 is a combined residual-current device and miniature circuit breaker (RCBO) — an FI/LS-protector Type A (PSE/SSF) — rated IΔn 30 mA, 6 kA breaking capacity, 1+N-pole, C characteristic 20 A. The 30 mA trip sensitivity covers personnel protection against direct contact (IEC 60364-4-41), while the 6 kA short-circuit rating coordinates with typical domestic and light commercial service entrances. Type A detection handles pulsating DC fault currents from single-phase rectifiers, so it is suited for circuits feeding electronic loads like washing machines, LED drivers, or small VFDs.
What the ratings mean for fit
The C-curve 20 A overcurrent characteristic means the magnetic trip fires at 5–10× In (100–200 A), sized for motor and lighting loads with moderate inrush. The 30 mA residual sensitivity is the standard for socket-outlet circuits in residential and commercial panels per IEC 60364. The 6 kA breaking capacity (Icn) is adequate for most TN and TT systems where the prospective short-circuit current at the board does not exceed that level; if your service entrance fault level is higher, step to a 10 kA rated RCBO. The 1+N-pole format switches the line conductor and breaks the neutral — common in single-phase final circuits where neutral switching is required for full isolation.
Panel integration
The 70 mm depth (D=70mm) is the standard for Siemens 5SU series RCBOs, fitting flush in distribution boards designed for that module depth. Snap-on mounting to DIN rail EN 60715; no additional busbar or bridging required for the 1+N configuration — the neutral pole connects via the plug-in neutral bar in the panel.