What it is and what the ratings mean
The Siemens 5SU1356-7KV06 is a combined residual current device and miniature circuit breaker — an RCBO — in a single 1+N-pole module with a Type A residual current characteristic, 30 mA sensitivity, 6 kA short-circuit breaking capacity, and a C-curve thermal-magnetic trip set at 6 A. Type A detection means it responds to sinusoidal AC fault currents and pulsed DC fault currents up to 6 mA of smooth DC superimposed — the kind a single-phase rectifier or a VFD front end can inject onto the line. The 30 mA trip threshold is the standard for personal protection against indirect contact in most IEC 60364 installations. The 6 kA rating at the declared voltage tells you it can safely interrupt a fault up to that prospective level without welding its contacts or bursting the arc chamber; downstream coordination with a higher-rated upstream MCCB or fuse is still needed if the available fault current exceeds that figure.
Where it goes and how it mounts
This RCBO snaps onto a standard 35 mm DIN rail inside a distribution board or sub-panel. The 70 mm depth (D=70mm) fits most shallow enclosures, but check the gland-plate clearance if you're retrofitting into a crowded cabinet. The 1+N-pole format occupies a single module width and switches the line conductor only; the neutral is switched internally for isolation but is not protected against overload. Rated for 50/60 Hz networks, it's a direct fit for residential, commercial, and light industrial final circuits — lighting, socket outlets, small motor loads up to 6 A.