What this part is — and isn't
The Siemens 3VA1110-1AA42-0CA0 is a SENTRON 3VA1 switch disconnector in the IEC frame 160 footprint, rated for 100 A continuous current (Iu) with 4 poles. It carries no overload or short-circuit protection — the designation "SD100" and the description confirm it is a pure disconnect, not a molded case circuit breaker. The built-in undervoltage release (UVR) is factory-set for 120-127 V AC 50/60 Hz, so the switch drops open when control voltage falls below the dropout threshold. This makes it a load-break switch for isolation and safety disconnection, not a protective device.
Key ratings and what they mean for fit
Rated continuous current Iu is 100 A — that is the maximum current the switch can carry continuously without exceeding temperature limits. The 4-pole configuration handles three-phase plus neutral (or a second pole for DC switching). Max rated operational voltage is 690 V AC 50/60 Hz and 600 V DC, so it covers standard 400/480 VAC panels and many DC bus applications up to 600 V. The IP40 front protection means it is suitable for enclosed panel mounting where no water jets or dust ingress are expected. Power loss is 38 W maximum at rated current — factor that into enclosure thermal calculations.
Mounting and integration
Dimensions are 70 mm deep, 101.6 mm wide, and 130 mm high. The main circuit connection is busbar connection with front terminals — designed for direct busbar mounting or panel wiring. The 4-pole width (101.6 mm) is wider than the 3-pole variants (76.2 mm), so a panel cutout or DIN-rail layout planned for a 3-pole MCCB will need extra space. The UVR coil wiring terminates at the front; no auxiliary contacts are included (auxiliary contact version is "Without"). An optional motor drive can be added (product extension optional).