What the ratings mean for fit
The Siemens 3VA1112-5EF32-0AF0 is a SENTRON molded case circuit breaker (MCCB) rated for 125 A continuous current (Iu) across ambient temperatures up to 50 °C, then derating linearly to 112.5 A at 70 °C. That 125 A figure is the headline for BOM fit — it sets the upstream conductor and downstream load current the breaker must carry without tripping under normal conditions. Breaking capacity is the real differentiator here: 187 kA at 240 V, 121 kA at 415 V, 75.6 kA at 440 V, and 17 kA at 690 V. Those numbers mean this breaker can safely interrupt fault currents up to those levels without welding contacts or venting plasma — critical for high-fault installations like transformer secondaries or large motor control centers where available fault current exceeds 65 kA. The TM240 overcurrent release is a fixed thermal-magnetic trip unit — no electronic adjustment, no communication module, no ground-fault monitoring. That keeps the part simple and reliable for line-protection duty where you don't need selective coordination curves or remote monitoring. The 1 auxiliary switch + 1 trip alarm switch (HQ version) provides local status feedback and a separate alarm contact for the trip event.
Panel fit and integration
Width is 76.2 mm, depth is 70 mm. Front IP40 rating. Operating temperature range is -25 °C to 70 °C, storage from -40 °C to 80 °C. That covers most indoor industrial environments; if the panel sits in an unheated warehouse, the -25 °C floor is worth noting for cold-start coordination. No undervoltage release, no shunt trip, no communication function — this is a pure thermal-magnetic MCCB for basic overcurrent protection. If your design requires remote trip or undervoltage lockout, you'll need a different variant or an add-on accessory.