What this 3VA1 is — and the spec that decides fit
The Siemens 3VA1140-5EF32-0DA0 is a SENTRON molded case circuit breaker (MCCB) built for line protection in distribution panels. It carries a TM240 thermal-magnetic overcurrent release, rated 40 A continuous at 40 °C and derated to 37 A at 70 °C — the thermal curve matters if your enclosure runs hot. Three poles, no communication function, no ground-fault monitoring. The undervoltage release (UVR) is factory-fitted, so this unit trips on loss of control voltage; that's a deliberate choice for applications where undervoltage protection is mandatory. The interrupting ratings are the headline: 187 kA at 240 V, 121 kA at 415 V, 75.6 kA at 440 V, and 17 kA at 500 V and 690 V. Those numbers tell you this breaker handles high available fault current on the secondary side of a large transformer — it's not a branch-circuit MCCB for a light load. Rated insulation voltage is 800 V, so it's comfortable in 480/277 V or 600 V panels with headroom. Dimensions: 130 mm tall, 76.2 mm wide, 70 mm deep. That 76.2 mm width (3 inches) is a standard 3-pole MCCB footprint — it fits Siemens 3VA1 panelboards and switchboards without adapters. Max power loss is 13.3 W at rated load, which is modest for a 40 A frame; ventilation in a sealed enclosure is still advisable if you're stacking breakers.
Integration notes for the panel
Mounts in a standard 3-pole MCCB cutout. The 70 mm depth leaves clearance for rear-connected busbars in most switchboards. The UVR coil draws continuously when the control voltage is present; verify your control transformer can supply the inrush without dropping below the dropout threshold. No communication module on this variant — if you need remote trip indication, order the auxiliary switch separately and wire it to a PLC input. Operating temperature range is -25 °C to 70 °C; storage from -40 °C to 80 °C. That covers most indoor panel environments. The TM240 release is fixed thermal-magnetic — no electronic adjustment, no zone-selective interlocking. Set it and forget it, but coordination studies need to account for the fixed curve.