What it is and what the ratings mean for fit
The Siemens 5SL3416-7 is a SENTRON miniature circuit breaker — a 4-pole, C-curve 16 A device rated for 400 V AC service. The 4.5 kA breaking capacity per EN 60898 covers residential and light commercial panelboards; the 5 kA rating per IEC 60947-2 gives a little more headroom for industrial distribution where fault currents may run higher. The C-curve (5–10× In magnetic trip) is the standard choice for general-purpose loads — lighting, small motor circuits, socket outlets — where inrush isn't extreme but you still want fast clearing on a hard short. Rated for 400 V AC multi-phase operation, with a maximum of 440 V AC, it handles 50/60 Hz supply. The 4-pole design switches all three phases plus neutral, which is typical for three-phase distribution in European-style panelboards. Mechanical service life is 10,000 operating cycles typical — fine for a distribution board that sees infrequent switching; not a part you'd cycle daily as a motor starter.
Where it goes and how it mounts
Mounts on a DIN rail in any position — no top-feed restriction. The 72 mm width (4 modular units) occupies standard panel space; depth is 76 mm, installation depth 70 mm. IP20 with connected conductors means it's protected against finger contact once wired, but not against dripping water — keep it inside an enclosure rated for the environment. Sealable with a lockable cover, halogen-free and silicon-free construction. Accepts supplementary devices (shunt trip, auxiliary contacts) on the side. Degree of pollution 2, overvoltage category III — suitable for fixed installations downstream of the main distribution board.