What this part is and what it isn't
The Siemens 3VA1110-1AA42-0JA0 is a SENTRON switch disconnector built in an MCCB form factor — same frame, same DIN-rail footprint, but with a critical difference: it provides no overload protection and no short-circuit protection. Rated for 100 A continuous current (Iu) across 4 poles, it's a manual isolation and switching device, not a circuit breaker. The shunt trip release (STL) rated 110-127 V DC/AC lets you trip it remotely, which is the main reason you'd spec this over a plain handle-operated disconnect.
Ratings and what they mean for fit
Rated continuous current Iu of 100 A means it carries that load continuously without derating in a 40 °C ambient — the same thermal backbone as the 3VA1 MCCB line. Max AC operational voltage is 690 V 50/60 Hz, and DC max is 600 V, so it covers 480 V and 600 V AC panels cleanly, and DC bus isolation up to 600 V. The 4-pole variant handles three-phase-plus-neutral isolation, common in North American and European distribution panels where the neutral must be switched for full isolation. IP40 on the front means it's protected against tools and wires >1 mm, but not against water ingress — panel builders should mount it in an enclosure rated for the environment. Busbar connection on the front terminals means it's designed for horizontal busbar systems typical in switchboard and panelboard builds, not for cable lugs out of the box.
Panel fit and integration
Width is 101.6 mm (4 inches), depth 70 mm, height 130 mm — the 4-pole variant takes up two extra pole spaces compared to the 3-pole 3VA1 siblings, so check your panel cutout and busbar staging before committing. The nut keeper kit is included in the order code, which simplifies busbar mounting on the front terminals. No auxiliary contacts are fitted (0 CO contacts), and no communication module is available on this variant — it's a pure disconnect with remote trip capability.