What this part is and what it does
The Siemens 3VA1110-1AA42-0HC0 is a SENTRON switch disconnector built on the 3VA1 IEC frame 160 platform, rated for 100 A continuous current (Iu) across four poles — three phases plus a switched neutral, which is the standard configuration for a 4-pole disconnector in a three-phase distribution panel. Unlike a molded-case circuit breaker, this unit provides no overload or short-circuit protection; it is a pure isolation and switching device, intended for manual or remote load-break and safety disconnection where the upstream protection is handled separately. The shunt trip release (STL) allows remote tripping on a 12-30 V DC or 24 V AC control signal, making it suitable for emergency-stop circuits or automated disconnection sequences in panel builds.
Key ratings and what they mean for fit
Rated continuous current Iu of 100 A defines the maximum uninterrupted load this disconnector can carry without exceeding its thermal limits — sized for a 100 A feeder or downstream distribution sub-panel. The limited short-time withstand ratings of 2 kA at both 1 s and 0.5 s confirm the disconnector can survive a fault current of that magnitude for the stated duration while the upstream breaker clears — critical for selectivity coordination in a distribution board. Rated insulation voltage Ui of 800 V and max operational voltages of 690 V AC and 600 V DC cover most industrial panel voltages. The 38 W maximum power loss at rated current means the disconnector dissipates heat into the enclosure — factor this into the panel's thermal budget, especially in a sealed cabinet with multiple devices. Mechanical endurance of 15 000 operating cycles is typical for a switch disconnector in this frame class — adequate for daily switching in a distribution panel but not for high-cycle process applications.
Where it fits in the panel
Dimensions of 70 mm deep, 101.6 mm wide, and 130 mm high place it in the standard 3VA1 frame footprint. Front terminal arrangement for the main circuit with busbar connection means the line and load conductors connect at the front face, and the unit is designed to plug onto a busbar system — common in Siemens SENTRON distribution boards. IP40 protection on the front is standard for indoor panel mounting — no washdown rating, so keep it inside a closed enclosure. The two HQ auxiliary switches provide two changeover (CO) contacts for status feedback to a PLC or indication lamp — wired via the front-accessible terminals.