Not for motor starting; that needs a C or D curve. Mounting position is unrestricted — vertical, horizontal, upside-down — which helps when you're packing a crowded panel. The IP20 rating applies with conductors connected; that's normal for a distribution board interior.
The single-phase AC voltage rating is 230 V (253 V max), and multi-phase (line-to-line) goes to 440 V. For DC circuits, the maximum voltage is 72 V — that's the limit for the single-pole break; beyond that you need series poles or a DC-rated breaker. Breaking capacity is 3 kA per IEC 60947-2. That's the industrial standard for the rating, not the domestic EN 60898 standard (which would be lower). In a residential or light-commercial distribution board with a typical upstream transformer impedance, 3 kA is adequate for most branch circuits. If your available fault current is higher — say a large transformer close to the panel — you'd step up to the 6 kA or 10 kA versions in the same SENTRON family. Mechanical endurance is 4,000 switching cycles. For daily on/off duty, add a contactor ahead of it.
Physical and environmental
The 5SL1125-6MB measures 18 mm wide, 90 mm tall, and 76 mm deep (70 mm installation depth behind the panel face). Pollution degree 2 (normal, non-conductive) and overvoltage category III (distribution level). Sealable — you can lock the toggle position with a seal wire for anti-tamper.