The Siemens 5SY4563-8CV is a miniature circuit breaker (MCB) with a D63 characteristic, rated for 1-pole-plus-neutral (1P+N) operation and a 15 kA interrupting capacity at 230/400 V.
In a panel with a transformer-fed bus that can deliver 15 kA of prospective short-circuit current, this MCB clears the fault within its rating — no cascading failure upstream. The 1P+N configuration switches the line conductor only; the neutral is switched but not protected, which is standard for single-phase branch circuits where the neutral is bonded to ground at the source.
Panel integration
Snap-on DIN rail mounting, standard 1-module width per pole. The D63 rating draws 63 A continuous — verify the busbar and downstream conductor ampacity match. In a crowded enclosure, the 15 kA interrupting rating holds without additional current-limiting fuses upstream, saving DIN space.