The Siemens SENTRON 3VA2440-5MN32-0BC0 is a 3-pole molded case circuit breaker (MCCB) rated at 400 A continuous current, designed specifically for motor protection. It carries a flat 400 A rating across the entire 40 °C to 70 °C ambient range — no derating needed in a warm panel, which simplifies the thermal coordination study on a motor control center lineup. Interrupting capacity runs from 187 kA at 240 V down to 9 kA at 690 V. At the common 415 V / 440 V industrial distribution level it delivers 121 kA — high enough to back a transformer-fed main without a current-limiting fuse upstream in most installations.
Auxiliary and undervoltage release configuration
Factory-fitted with two HQ auxiliary switches and an undervoltage release (UVR). The UVR trips the breaker when control voltage drops below the dropout threshold — standard practice for emergency-stop chains and undervoltage protection on motor feeders. The HQ auxiliary contacts provide status feedback for the PLC or DCS without adding a separate contactor block.
Dimensions and panel fit
Footprint is 138 mm wide by 248 mm tall by 110 mm deep. That width matches the standard SENTRON 3VA4 frame spacing on a DIN rail or bolted bus.
Phase-failure detection is built in, and the design includes undervoltage release as standard — two features that matter for motor protection on three-phase feeders where a lost phase can single-phase the load. Communication function is not fitted on this variant; it is a standalone thermal-magnetic or electronic-trip MCCB with hardwired aux contacts.