Siemens 3VA1140-4EF36-0DA0 — 40 A MCCB with undervoltage release
The Siemens SENTRON 3VA1140-4EF36-0DA0 is a 3-pole molded case circuit breaker (MCCB) rated for 40 A continuous current at 40 °C, with the TM240 thermal-magnetic overcurrent release. It carries an undervoltage release (UVR) as the integrated auxiliary release — no separate undervoltage module needed. Breaking capacity hits 121 kA at 240 V and 75.6 kA at 415 V, so it handles high-fault service-entrance or distribution panels without cascading upstream. This is the line-protection version, meaning it's set up for cable and busbar protection in a main or subfeed panel, not motor-circuit protection. No communication function, no phase-failure detection, no ground-fault monitoring — it's a straightforward thermal-magnetic breaker with the UVR as the only accessory built in.
Ratings and what they mean on the panel
The 40 A rating holds flat from 40 °C up to 50 °C — no derating needed in a typical warm enclosure. Above 55 °C it steps 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 your panel ambient runs over 50 °C, size the breaker for the derated figure, not the nameplate 40 A. Breaking capacity varies sharply with system voltage: 121 kA at 240 V, 75.6 kA at 415 V, 52.5 kA at 440 V, 11.9 kA at 690 V. At 690 V it's still adequate for most industrial distribution, but verify your available fault current against the 11.9 kA ceiling. Rated insulation voltage is 800 V, so the breaker is rated for 690 V line-to-line systems. The IP40 front protection means it's splash-proof on the front face but not sealed against hose-down — mount inside a panel with a door.
Panel fit and integration
Footprint is 76.2 mm wide (3-pole), 130 mm tall, 70 mm deep. That's a standard MCCB cutout — drops into the same panel space as other 3VA1 frames. No auxiliary contacts fitted, so if you need status feedback to a PLC, you'll add the 3VA9608-0BB25 auxiliary trip block or a separate auxiliary switch. The undervoltage release is wired separately from the main power path — it's a shunt-style UVR that trips the breaker when coil voltage drops below the dropout threshold. Verify your control voltage matches the UVR coil rating (not listed here, but standard 24 VDC or 230 VAC per the 3VA family). No trip indicator on the front — you'll see the handle position, but no red/green flag.