MCCB selection memo — 3VA1332-6FF42-0AA0
The Siemens SENTRON 3VA1332-6FF42-0AA0 is a 4-pole molded case circuit breaker rated at 160 A continuous, with a TM240 thermal-magnetic trip unit. The 154 kA breaking capacity at 415 V AC means it can safely interrupt fault currents up to that level on a 400 V distribution bus without upstream cascading — a key spec for high-fault panels behind a large transformer. The 320 A thermal rating at 40 °C (derated to 292 A at 70 °C) governs the actual continuous load it can carry in a warm enclosure; that derating curve is what a panel designer sizes against, not the 160 A nameplate.
Panel fit and integration
Dimensions are 248 mm high × 184 mm wide × 110 mm deep. The depth is the key clearance dimension for a shallow backpanel enclosure — 110 mm means it fits a standard 200 mm deep cabinet with room for rear wiring gutters. The IP40 front face is splash-protected for general indoor panel use but not washdown; mount it behind a gland plate or enclosure door in wet environments.