What it is and what it does
The Siemens 3VA1140-4EF36-0JC0 is a SENTRON molded case circuit breaker (MCCB) for line protection in distribution panels. It carries a rated continuous current of 40 A across ambient temperatures up to 50 °C, then derates to 36 A at 70 °C — so for a panel running warm, plan on 36 A continuous, not the full 40 A. The TM240 thermal-magnetic release handles overload and short-circuit protection without a separate trip unit. Interrupting capacity is the headline here: 121 kA at 240 V, 75.6 kA at 415 V, 52.5 kA at 440 V, and 11.9 kA at 690 V. That 121 kA at 240 V means it can clear a high-fault bolted short without the arc flashing over — critical for transformer-secondaries or busway-fed panels where available fault current runs high.
Panel fit and integration
Three-pole, 70 mm deep, 76.2 mm wide, 130 mm tall. That 76.2 mm width is a standard 3-pole MCCB footprint — it drops into a SENTRON panelboard or a DIN-rail adapter without re-drilling. The IP40 front protection means it's fine for a dry indoor enclosure; no washdown rating, so keep it behind a gland plate in clean environments. Rated insulation voltage is 800 V, which covers 480/277 V and 600 V systems with margin.