What this part is and what it does
The Siemens 3VA1110-1AA42-0DA0 is a SENTRON 3VA1 switch disconnector in MCCB-style design, built on the IEC frame 160 platform. It is a 4-pole unit rated for 100 A continuous current (Iu) without integrated overload or short-circuit protection — it functions purely as a disconnect switch, not a circuit breaker. The part ships with an undervoltage release (UVR) coil rated 208-230 V AC 50/60 Hz, which automatically opens the switch when control voltage drops below the dropout threshold. Rated insulation voltage is 800 V (Ui), and maximum rated operational voltage reaches 690 V AC or 600 V DC. The front face carries IP40 protection. Main circuit connections are busbar-style front terminals.
What the ratings mean for panel fit
At 70 mm deep, 101.6 mm wide, and 130 mm tall, this 4-pole switch disconnector occupies the same DIN-rail footprint as the 3VA1 MCCB family. The 101.6 mm width (4 inches) is the standard 4-pole width for the IEC frame 160 — it will fill four module spaces on a DIN rail. Verify gland plate clearance for the front busbar terminals; the depth leaves room behind a 200 mm deep enclosure door. Maximum power loss is 38 W at rated current. In a sealed enclosure with multiple devices, that heat needs to be factored into the thermal budget — derate ambient if the panel exceeds 70 °C operating maximum.
Key selection detail: no overcurrent protection built in
This is a switch disconnector, not a molded case circuit breaker. It has no thermal-magnetic or electronic trip unit. The description explicitly states "without overload protection" and "without short-circuit protection." It is intended for isolation and switching duty where overcurrent protection is provided upstream or by a separate device. The UVR coil is the only integrated release — it drops the switch on undervoltage or remote trip via the control circuit.