What this RCBO does in the panel
The Siemens 5SV9316-1NK20 is a 1P+N RCD-operated circuit breaker (RCBO) from the SENTRON 5SV9 series, combining overcurrent protection and residual current detection in a single 18 mm wide module.
Current derating and thermal reality
At 40 °C it derates to 19 A, at 45 °C to 18.4 A, and at 50 °C to 18 A. At 55 °C — the top of the operating range — it's 17.4 A. Power loss is 3.8 W maximum, which matters when packing multiple RCBOs in an enclosure — heat buildup accelerates the derating curve.
Wire termination and physical fit
That covers most final subcircuit wiring — 1.5 mm² for lighting, 2.5 mm² for socket outlets, 4 mm² or 6 mm² for heavier loads, and 10/16 mm² for submain feeds where an RCBO is used as a main switch. Depth is 77 mm, installation depth 70 mm, height 90 mm. The 18 mm width equals one modular unit (1 MW), so it occupies a single pole position on a DIN rail.