The Siemens 3VA1112-1AA32-0HC0 is a SENTRON switch disconnector built in MCCB (moulded-case circuit breaker) design, but configured without overload or short-circuit protection — it is a pure disconnect, not a breaker. This is a load-break switch for isolation and switching duty, sized for IEC frame 160, and carries a shunt trip (STL) coil for remote tripping plus two HQ auxiliary switches for status feedback.
That simplifies BOM sizing: if your load pulls 125 A or less, this disconnect handles it at any ambient within that band. Insulation voltage of 800 V means the internal clearance and creepage are designed for 800 V class, so it is comfortable on 690 V systems without voltage stress concerns. Power loss is 38 W maximum at rated current. That matters for enclosure thermal management — a 125 A disconnect dumping 38 W into a small stainless enclosure may need ventilation or derating of adjacent devices. The IP40 front protection means it is splash-proof from the front but not hose-down; suitable for indoor panel mounting, not washdown zones.