The Siemens 5SU1353-6KV13 is a combined residual-current and miniature circuit breaker (RCBO) — an FI/LS protector — in a single 1+N-pole module. It carries Type A (PSE/SSF) sensitivity at 30 mA, a B-curve trip characteristic rated 13 A, and a 4.5 kA breaking capacity. The D=70 mm dimension refers to the depth behind the panel, which governs the enclosure depth needed for flush-mounting in a consumer unit or distribution board.
What the ratings mean for fit
The B-curve (13 A) trips between 3 and 5 times rated current, which is the standard choice for resistive and general-purpose loads in residential and light commercial panels — it handles inrush from lighting and small transformers without nuisance trips. The 30 mA Type A residual-current element detects sinusoidal AC faults plus pulsating DC faults (common from rectified loads like LED drivers, washing machines, and EV chargers), which is why the description flags PSE/SSF (pulsating-sensitive / smooth-sensitive fault). The 4.5 kA breaking capacity is the standard domestic rating for UK and European distribution boards; it safely interrupts a short-circuit fault up to that level without upstream cascading.
Panel integration
The 1+N-pole format occupies a single module width on a DIN rail. The 70 mm depth means the part projects 70 mm behind the mounting rail — check that the enclosure or consumer unit has at least that internal clearance before specifying. The outgoing neutral is switched internally, so no separate neutral bar connection is needed downstream of the device.