What it is and what it does
The Siemens SENTRON 3VA1110-1AA42-0KA0 is a 4-pole switch disconnector built in an MCCB (moulded-case circuit breaker) form factor — meaning it occupies the same panel footprint and busbar connection pattern as a standard 4-pole breaker, but its primary job is load-break isolation rather than overcurrent protection. Rated for 100 A continuous current (Iu) across the full ambient range from 40 °C through 70 °C, it handles motor, resistive, and general distribution loads where a visible-break disconnect is required by code or safety practice.
Key ratings and what they mean for fit
The 100 A rating is flat — no derating needed from 40 °C up to 70 °C, which is unusual for a compact disconnect. That means you can install it in a warm enclosure or next to heat-generating gear without recalculating the load schedule. The 690 V AC (50/60 Hz) and 600 V DC maximum operational voltages cover most industrial supply voltages, including 480Y/277 V and 600 V delta systems common in North American panels, as well as 400 V and 690 V IEC distribution. The shunt trip release (STL) lets you remotely trip the disconnect via a control voltage — useful for emergency-stop circuits or PLC-controlled isolation sequences. There is no undervoltage release, no auxiliary contacts, and no communication module on this variant; it is a pure disconnect with a remote-trip coil. If you need auxiliary signalling or undervoltage protection, you would look at a different configuration within the 3VA1 family.
Where it goes in the panel
This disconnect connects via busbar to the main current circuit, with front terminals for incoming and outgoing conductors. The 101.6 mm width (4-inch, 4-module DIN footprint) matches standard 4-pole MCCB cutouts. Depth is 70 mm, height 130 mm — it fits most distribution panelboards without crowding the gland plate. The front face carries IP40 protection, meaning it is protected against tools and wires over 1 mm but not sealed against water; install it inside an enclosure rated for the environment.