What this MCCB delivers
The Siemens 3VM1140-3ED16-0AA2 is a 1-pole SENTRON molded case circuit breaker rated 40 A at 40 °C, with a TM210 thermal-magnetic release. It interrupts 53 kA at 240 V AC and 8 kA at 415 V AC — the 415 V figure governs most European industrial panel applications, while the 240 V rating covers North American 120/240 V split-phase or 277/480 V wye-derived single-pole branch circuits. Thermal derating is flat from 40 °C to 50 °C at 40 A, then steps down to 39 A at 55 °C, 38 A at 65 °C, and 37 A at 70 °C. That means the breaker holds its full rating across typical panel ambient without oversizing — useful when the MCCB shares a crowded enclosure with other heat sources. At 25.4 mm wide (1 inch), it occupies a single pole space on a DIN rail, with a depth of 70 mm from the mounting surface to the front of the housing. The IP40 front protection keeps out tools and finger contact during panel work.
Coordination and selectivity note
The TM210 release is a fixed thermal-magnetic design — no interchangeable trip units, no communication module, no undervoltage release. That simplifies ordering but locks the protection curve; if your design requires adjustable long-time pickup or ground-fault, step up to the 3VA series with electronic trip units. Rated insulation voltage is 500 V AC, and the maximum operational voltage is 415 V AC (125 V DC). The 8 kA breaking capacity at 415 V AC is sufficient for most secondary distribution panels downstream of a larger main breaker; verify the available fault current at the point of installation before committing the BOM line.
Sourcing and lifecycle
For a direct functional cross-reference within the Siemens MCCB family, the 3VA1020-3ED36-0AA0 is a 1-pole, 40 A, 25 kA at 415 V AC unit with an electronic trip. The 3VM holds a higher interrupting rating (53 kA at 240 V) and uses a simpler thermal-magnetic release; the 3VA offers adjustable trip settings and a higher 415 V breaking capacity. Verify footprint compatibility — the 3VA series shares the same 25.4 mm width and DIN-rail mount, but the depth and terminal layout differ slightly.