What this part is and what it does
The Siemens 3VA1110-1AA36-0HC0 is a 3-pole switch disconnector from the 3VA1 series, built on the IEC frame 160 platform and rated at 100 A. It serves as a manual load-break disconnect for isolating circuits under load, with no overload or short-circuit protection integrated — that means it is a pure disconnecting means, not a motor-protective device. The shunt trip (STL) coil, rated 12–30 V DC or 24 V AC 50/60 Hz, lets you trip it remotely from a safety circuit or E-stop chain, which is the main reason you spec this variant over a plain handle-operated switch.
Where it fits in the panel
Clamp connection terminals accept copper conductors typical for a 100 A feed. The 3VA1 frame footprint matches Siemens standard switch-disconnector cutouts and DIN-rail adapter plates, so it swaps into existing 3VA or 3KD panel layouts without re-drilling the gland plate. The two HQ auxiliary switches give you a positive status feedback pair — one N/O, one N/C — for the PLC to confirm the disconnector is open or closed, which closes the safety loop without a separate limit switch.