The Siemens 5SY4315-8CV is a 3-pole miniature circuit breaker (MCB) with a D-curve trip characteristic rated at 1.6 A.
The D-curve (1.6 A rated current) means the magnetic trip threshold is set at 10–20 times In, so it tolerates high inrush currents from motor loads, transformers, or discharge lighting without nuisance tripping. For a 1.6 A rating, that magnetic trip point sits between 16 A and 32 A.