What the ratings mean for fit
The SENTRON 3VA2340-5JQ42-0CA0 is a 4-pole molded case circuit breaker (MCCB) rated 400 A at 40 °C, holding that rating flat through 50 °C before it starts to derate — 375 A at 55 °C, 350 A at 60 °C, 325 A at 65 °C, and 300 A at 70 °C. That thermal curve tells you the breaker is sized for a 400 A continuous load in a 50 °C panel ambient; above that, you lose 25 A per 5 °C step. The interrupting ratings are the headline: 187 kA at 240 V, 121 kA at 415 V and 440 V, 75.6 kA at 500 V, and 7.5 kA at 690 V. For a 400 A frame, those numbers mean it handles high-fault utility feeds or transformer secondaries without cascading upstream — the 187 kA at 240 V is essentially unlimited-available-current territory for most North American 240 V delta services.
Panel integration and wiring
The breaker measures 110 mm deep, 184 mm wide, and 248 mm high — a 4-pole frame that fits standard SENTRON mounting patterns. It's a panel-mount MCCB, not a DIN-rail snap-on; you'll bolt it to a backplate or mount it in a SENTRON distribution board. The undervoltage release (UVR) is built in, so if the control voltage drops, the breaker trips — that's a safety interlock for motor control centers or emergency-stop circuits. Communication function is present, meaning it can integrate with a higher-level monitoring system for power metering or remote trip indication. Maximum power loss is 98.5 W at rated load — factor that into enclosure thermal calculations if you're stacking multiple breakers in a sealed cabinet.