The Siemens 3VA1112-1AA36-0DH0 is a SENTRON 3VA1 switch disconnector in an MCCB-style housing — IEC frame 160, three poles, rated for 125 A continuous current (Iu). It is a pure disconnect: no overload or short-circuit protection built in, so it functions as a manual load-break switch for isolation and switching of circuits where the upstream protection handles the fault clearing.
Undervoltage Release and Auxiliary Contacts
No leading contact on the UVR, so the coil must be energized before the main contacts close. Auxiliary contact configuration is 2 form-C auxiliary switches plus 1 form-C trip alarm switch, all HQ (high-utilization) rated. The trip alarm switch changes state only on a UVR-triggered opening, not on manual operation — useful for distinguishing a fault trip from a normal shutdown.
Footprint is 76.2 mm wide (3-inch grid compatible), 130 mm tall, 70 mm deep — same mechanical envelope as the 3VA1 MCCB line. The front terminals are accessible with the panel door closed, so wiring checks don't require removing the device.