40 A MCCB with 220 kA interrupting capacity — what that means for your panel
The Siemens 3VA1140-6EF36-0AA0 is a 3-pole SENTRON molded case circuit breaker (MCCB) rated for 40 A continuous at 40 °C, carrying the full 40 A all the way up to 50 °C before a slight derate begins (39 A at 55 °C, 37 A at 70 °C). That thermal curve means it holds its rating across most standard panel ambient temperatures without forced cooling. The interrupting capacity is the headline number here: 220 kA at 240 V, dropping to 154 kA at 415 V and 121 kA at 440 V. At 500 V and 690 V it still clears 17 kA. For a 40 A frame, that 220 kA figure means this breaker can sit upstream of a high-fault transformer or feed a bus where the available fault current is extreme — you don't need a current-limiting fuse ahead of it in most installations. It's designed for line protection (not motor or generator protection) with a TM240 thermal-magnetic overcurrent release. That fixed thermal element and magnetic trip pair is the workhorse choice for feeder and distribution panels where you want simple, reliable coordination without electronic adjustment.
DIN-rail integration and panel fit
At 76.2 mm wide (3 in), 130 mm tall (5.12 in), and 70 mm deep (2.76 in), this MCCB mounts on a standard DIN rail — the 3-pole width is a compact 3-module footprint, so it slots into a panel without eating up more rail than a 40 A breaker should. The front face carries IP40 protection, meaning tool-proof fingers won't reach live parts, but it's not sealed against washdown. No undervoltage release, no shunt trip, no communication module, and no ground-fault monitoring on this variant — it's a straight thermal-magnetic breaker with no auxiliaries built in. If you need remote tripping or status feedback, you're adding external accessories or stepping up to the electronic-trip version in the 3VA family.