What it is and what it does
The Siemens 5SV9316-7NK16 is a SENTRON RCBO — an RCD-operated circuit breaker that combines overcurrent protection and residual current detection in a single 18 mm-wide module. It's a 1P+N design (switches the line, monitors both line and neutral), rated 16 A at 30 °C with a C-curve trip characteristic. The C-curve means it holds up to 5–10× In for short-duration inrush (typical for motor starters and small transformers) before tripping instantaneously on a hard fault. Breaking capacity is 6 kA per both EN 60898 and IEC 60947-2 — enough for most residential and light commercial distribution boards where the prospective fault current stays under that threshold. The 6 kA rating is the same under both standards, so you don't need to derate when specifying across European and international specs.
Mounting and integration
Snaps onto standard 35 mm DIN rail, occupies one modular width (18 mm). Depth is 77 mm, installation depth 70 mm — fits standard distribution boards with 80+ mm enclosure depth. Mounting position is any, so it works in vertical or horizontal panel layouts. Supply can enter from top or bottom, which saves wire routing time on a crowded rail. IP20 rating applies when installed in a distribution board with connected conductors — standard for enclosed panel use. Degree of pollution 2 and overvoltage category III mean it's rated for fixed installations with transient overvoltages typical of mains supply. Halogen-free and silicon-free construction matters if the panel sits in a clean-room or semiconductor fab where outgassing is a concern.
Thermal performance and derating
The 16 A rating is at 30 °C ambient. At 40 °C it derates to 15.2 A, at 45 °C to 14.72 A, at 50 °C to 14.24 A, and at 55 °C to 13.76 A. If the panel runs hot — say, a packed enclosure with multiple RCBOs ganged — factor the derating into the load calculation. The 95% humidity tolerance covers damp environments like basements or outdoor-rated enclosures.