What it is — and what the ratings mean for fit
The Siemens SENTRON 3VA1140-6EF32-0DA0 is a 3-pole molded case circuit breaker (MCCB) rated for 40 A continuous current (Iu). It carries a TM240 thermal-magnetic release — the thermal element handles overloads, the magnetic element handles short-circuits — and includes an undervoltage release (UVR) that trips the breaker when supply voltage drops below a set threshold. That UVR is the 3VA9608-0BB25 auxiliary trip unit, integrated at the factory. Breaking capacity is the headline number here: 220 kA at 240 V, 154 kA at 415 V, 121 kA at 440 V, and 17 kA at 690 V. That means it can safely interrupt a fault current up to those levels at the respective voltage — critical for high-fault installations like transformer secondaries or large motor control centers where available fault current can exceed 100 kA. The 220 kA at 240 V figure is especially relevant for North American 240 V delta or 277/480 V wye systems where the line-to-ground fault can be severe. Thermal derating is published across the full operating range: full 40 A from 40 °C to 50 °C, then tapering to 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 ambient runs hot — say, a crowded enclosure near a furnace line — you need to account for that drop. The rated insulation voltage is 800 V, so it's comfortable on 690 V systems with margin.
Where it goes — panel integration and environment
This MCCB is designed for DIN-rail mounting in a distribution or motor control center panel. Dimensions are 70 mm deep, 76.2 mm wide, and 130 mm tall — a standard 3-pole MCCB footprint that fits most Siemens SENTRON panelboards and third-party enclosures with the appropriate busbar adapter. The front face carries an IP40 rating, meaning protection against tools and wires greater than 1 mm, but not against water ingress — keep it inside a rated enclosure. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C. That covers most indoor industrial environments, but if the breaker sits in an unheated warehouse or a refrigerated area, the storage low end is fine, but the operating minimum of -25 °C means it won't trip reliably below that — not an issue for most plants, but worth noting for cold-climate outdoor enclosures.