What it is and what it does
The Siemens 3VA1140-5EF36-0AC0 is a SENTRON molded case circuit breaker (MCCB) for line protection in distribution panels. It's a 3-pole unit rated for 40 A continuous current (Iu) with a TM240 thermal-magnetic trip unit — no electronic adjustment, no communication, just a straightforward overcurrent release that handles both thermal overload and magnetic short-circuit response.
Breaking capacity — the real-world interrupt rating
This MCCB carries a 187 kA interrupting capacity at 240 V, 121 kA at 415 V, 75.6 kA at 440 V, and 17 kA at 690 V. That 187 kA figure at 240 V means it can safely clear a fault up to that level without rupturing or welding contacts — critical for high-available-fault-current service entrances or transformer secondaries where the upstream utility can deliver a monster bolted fault. The steep drop at 690 V (17 kA) is typical for this frame size; if your panel feeds a 690 V motor drive, verify the available fault current is under that ceiling.
Current derating in a warm panel
Rated 40 A from 40 °C through 50 °C ambient. Above that it starts to step down: 38.4 A at 55 °C, 37.6 A at 60 °C, 36.8 A at 65 °C, 36 A at 70 °C. If this breaker sits in a crowded enclosure with drives or transformers radiating heat, use the 70 °C column as your planning number — that 36 A derated figure is the real continuous limit, not the 40 A on the nameplate.
Panel fit and integration
Front face rated IP40 — fine for a clean indoor panel, not for washdown zones. Dimensions: 130 mm height, 76.2 mm width (3-pole), 70 mm depth. That 70 mm depth is shallow enough to clear most backpanel wiring troughs without a spacer. Comes with 2 auxiliary switches (HQ type) pre-installed, so you've got status feedback to the PLC without adding a separate aux block.
What it does not have
No undervoltage release, no shunt trip, no ground-fault monitoring, no communication module, no phase-failure detection, no voltage trigger. No trip indicator on the front. It's a bare-bones line-protection MCCB — thermal-magnetic only. If your spec calls for electronic trip adjustment or remote tripping, this isn't the variant.