The Siemens 3VA2440-5MN32-0JC0 is a SENTRON molded case circuit breaker (MCCB) designed specifically for motor protection. It carries a continuous current rating of 400 A across the full ambient temperature range from 40 °C to 70 °C, meaning no derating is needed when installed in a warm panel — that 400 A holds all the way up to 70 °C. Breaking capacity is voltage-dependent: 187 kA at 240 V, 121 kA at 415 V and 440 V, 75.6 kA at 500 V, and 9 kA at 690 V. At typical 400 V industrial distribution, that 121 kA rating handles high-fault scenarios common behind large step-down transformers. This unit ships with a shunt trip (STL) release and two auxiliary switches (HQ type) already installed — no separate ordering or field fitting required. The shunt trip lets a remote PLC or safety relay drop the breaker on command, which is standard for emergency-stop circuits or interlocked machine zones.
Mounting and Integration
Dimensions are 248 mm high × 138 mm wide × 110 mm deep (9.76 × 5.43 × 4.33 in). The 110 mm depth is a standard panelboard fit — check gland-plate clearance if back-panel wiring is tight. Three-pole configuration with phase failure detection built in; undervoltage release is not fitted on this variant.
Key Specifications
Power loss at maximum rating is 63.5 W — account for that in panel thermal calculations if multiple breakers are ganged. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C. The short-time withstand rating is limited to 5 kA for 1 s. This is the motor protection design variant, not a standard feeder breaker. The internal electronic trip unit includes phase failure detection to protect three-phase motors from single-phasing. No communication function is built in — this is a standalone thermal-magnetic or electronic trip MCCB.