What the ratings mean for fit
The Siemens 5SY4604-7CV is a 3-pole-plus-neutral miniature circuit breaker with a C4 tripping characteristic and a 15 kA interrupting capacity at 400 V AC. The 15 kA Icu means it can safely clear a fault current up to that level without welding its contacts or rupturing the case — critical for installations where the prospective short-circuit current at the panel is high. The C4 curve (4x to 10x In) is the standard choice for moderate inrush loads like small motors, transformers, or capacitor banks; it holds through the startup surge but trips fast on a hard short.
Where it goes in the panel
Snap-on DIN rail mount, standard 18 mm per pole width. The 3P+N configuration occupies four modules. Rated for 400 V line-to-line, so it suits three-phase distribution boards in commercial or light industrial sub-distribution. The C4 curve keeps it selective with upstream C-curve or B-curve breakers in a typical radial topology.