The Siemens 3VA1112-1AA42-0AA0 is a SENTRON switch disconnector built in an MCCB-style housing — 4 poles, rated 125 A continuously from 40 °C through 70 °C ambient, with no overload or short-circuit protection (it is a disconnect-only device). The 70 mm depth and 101.6 mm width fit standard IEC distribution panel cutouts; the IP40 front protects against tool entry and solid objects larger than 1 mm.
That matters when the disconnector sits near transformers or other heat sources in a panel. The 4-pole configuration isolates all three phases plus neutral, typical for three-phase distribution with a switched neutral. No undervoltage release, no auxiliary switch, no trip indicator — this is a pure manual disconnect, not a motor-protective device. The mechanical life of 15 000 operating cycles is standard for a panel-mounted switch disconnector used for infrequent isolation, not daily switching. Maximum power loss of 38 W at rated current helps size enclosure ventilation.
Front-terminal busbar connection — the main circuit wires land on the front face, not the rear, which simplifies busbar routing in a distribution board. No auxiliary contacts or releases are included; if you need remote status or undervoltage trip, this variant does not carry them. An optional motor drive can be added later for remote switching.