What this MCCB carries — and what it means on the line
The Siemens 3VA2440-5HN32-0BA0 is a SENTRON molded case circuit breaker rated for 400 A continuous across the full 40 °C to 70 °C ambient range — no derating needed until you push past 70 °C, which is rare inside a ventilated enclosure. That flat thermal curve simplifies panel sizing: you don't have to oversize the frame for a warm cabinet. Breaking capacity climbs to 187 kA at 240 V, drops to 121 kA at 415 V and 440 V, then 75.6 kA at 500 V, and 9 kA at 690 V. That 187 kA at 240 V is high enough for most transformer-secondaries and large UPS feeds; the 121 kA at 415 V covers heavy industrial switchboards. The 9 kA at 690 V is the weak point — if your system runs 690 V with high fault current, this frame may not clear it. Check your available fault current at that voltage before committing the BOM line. Three-pole construction, line-protection design — meaning it's configured for feeder and main breaker duty, not motor protection (no thermal overload curve matched to a motor start profile). The built-in undervoltage release (UVR) trips the breaker when control voltage drops, which is standard for emergency-stop chains and safety disconnects where you want the breaker to open on loss of pilot power.