What this MCCB is and what it does
The Siemens 3VA2440-5JP32-0AA0 is a SENTRON molded case circuit breaker (MCCB) configured for line protection — the primary role is protecting cables and busbars against overload and short-circuit in a distribution panel. It carries a continuous current rating Iu of 400 A across the full ambient range from 40 °C to 70 °C, so no derating curve to chase for warm enclosures. The 3-pole design handles three-phase systems up to the rated insulation voltage Ui of 800 V. Breaking capacity is the headline number for an MCCB: this unit delivers 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. Those figures mean it can safely interrupt fault currents up to those levels without welding contacts or venting gas into the panel — critical when the available fault current at the service entrance is high. The electronic trip unit is an ETU550. N-conductor protection is adjustable from OFF to 20 % up to 160 %.
Panel integration and mounting
Dimensions are 248 mm high, 138 mm wide, and 110 mm deep — a standard SENTRON 3VA footprint that fits existing Siemens switchboard layouts and most DIN-rail or bolted-bus mounting schemes. The front face carries an IP40 protection rating, meaning tools and fingers are kept out but the breaker is not sealed against water ingress; it belongs in a closed panel, not a washdown zone. Maximum power loss at rated current is 63.5 W. That matters for thermal management inside a dense panel — adjacent devices and wire bending space need to account for the heat this breaker dumps into the enclosure.
Lifecycle and sourcing posture
The breaker includes a communication function for status and trip event reporting.