What this MCCB does on the line side
The Siemens SENTRON 3VA1140-3EF32-0HC0 is a 3-pole molded case circuit breaker rated for 40 A continuous current (Iu) with a TM240 thermal-magnetic overcurrent release. It's a line-protection device — meaning it sits upstream protecting a feeder or distribution bus, not a motor branch. The interrupting capacity scales with system voltage: 75.6 kA at 240 V, 52.5 kA at 415 V, 32 kA at 440 V, and 10.5 kA at 690 V. For a 400 V panel, that 52.5 kA rating clears most utility-fault scenarios without cascading upstream. The TM240 release means the thermal element handles overloads, the magnetic element handles short circuits, and both are factory-set, not field-adjustable. Mounts on a DIN rail or panel base. Dimensions are 130 mm high, 76.2 mm wide, 70 mm deep — the width is a standard 3-pole MCCB footprint, so it drops into existing SENTRON or 3VA panel layouts without re-drilling the gland plate. IP40 on the front means it's protected against tools and wires >1 mm, but not against water spray; keep it inside a rated enclosure.
Thermal derating and ambient limits
The 40 A rating holds flat from 40 °C to 50 °C ambient. Above that it derates: 38.4 A at 55 °C, 37.6 A at 60 °C, 36.8 A at 65 °C, and 36 A at 70 °C. If the panel runs hot — say next to a drive cabinet — size the upstream conductor for the derated current, not the nameplate 40 A. Operating range is -25 °C to 70 °C; storage range is -40 °C to 80 °C. The storage limit governs shipping and spares on the shelf, not running conditions.
Auxiliary and release options
This variant ships with 2 HQ auxiliary switches (high-rupturing-capacity contacts for signal feedback) and a shunt trip (STL) auxiliary release for remote tripping. The shunt trip is ordered separately as 3VA9688-0BL30 — it's a voltage-trigger coil that lets a PLC or E-stop pushbutton open the breaker. No undervoltage release, no ground-fault monitoring, no phase-failure detection, no communication module. It's a basic line-protection MCCB with remote-trip capability; if you need UVR or ground-fault, step to a different 3VA variant.