What this MCCB is and what it carries
The Siemens SENTRON 3VA2340-5JP32-0AG0 is a 3-pole molded case circuit breaker (MCCB) rated for 400 A continuous current, designed for line protection in distribution panels. It carries a breaking capacity of 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 — covering the voltage range from low-voltage switchgear up to 690 V industrial supplies. The trip unit is adjustable between 600 A and 4 000 A, so this frame can be set to protect a range of downstream loads without swapping the breaker body. A trip indicator is fitted, and the auxiliary switch configuration includes one auxiliary switch plus one trip alarm switch (HP type).
Thermal derating — what the continuous current actually means in your panel
The 400 A rating holds at ambient temperatures up to 50 °C. Above that, the breaker must be derated: 375 A at 55 °C, 350 A at 60 °C, 325 A at 65 °C, and 300 A at 70 °C. If your panel runs hot — near a transformer or in a crowded enclosure — the 55 °C derating to 375 A is the figure to design to, not the 400 A nameplate. The operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C. Maximum power loss at rated current is 96 W, which contributes to the enclosure's thermal budget.
Breaking capacity — selectivity and SCCR headroom
At 240 V the 187 kA rating is very high for this class — it allows the breaker to be used in high-fault locations like service entrances or transformer secondaries without cascading upstream. At 415 V and 440 V the 121 kA rating still covers most industrial distribution scenarios. The drop to 75.6 kA at 500 V and 7.5 kA at 690 V means you need to verify the available fault current at your specific system voltage; at 690 V the breaker is limited to relatively low-fault installations.
Panel fit and integration
Dimensions are 248 mm high, 138 mm wide, 110 mm deep. The breaker includes a communication function for remote monitoring and trip indication. No undervoltage release or ground-fault monitoring version is fitted on this variant; those are available as separate auxiliary releases if the application requires them.