What the ratings mean for fit
The Siemens SENTRON 3VA2340-5JQ42-0AB0 is a 4-pole molded case circuit breaker rated for line protection, carrying a continuous current of 400 A up to 50 °C without derating. Above that, the thermal curve drops to 375 A at 55 °C, 350 A at 60 °C, 325 A at 65 °C, and 300 A at 70 °C — so if your panel ambient runs hot, you lose capacity fast; size for the actual enclosure temperature, not the nameplate. Interrupting capacity is 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. That 187 kA at 240 V means it handles high-fault utility feeds without cascading upstream — common for large transformer secondaries or busway taps. The 7.5 kA at 690 V is still enough for most 690 V motor circuits, but verify your available fault current at that voltage. The breaker includes a communication function and ships with two HP auxiliary switches. The basic switch variant is 3VA2340-5JQ42-0AA0 — this order code adds the aux switches and comms. No undervoltage release or voltage trigger is fitted.
Lifecycle and sourcing reality
The lifecycle stage is marked current, meaning the manufacturer lists it as an active catalog item — no phase-out notice, no last-time-buy window. That's the cleanest status you can get for a BOM freeze: no looming PCN, no forced redesign. Sourced and quoted to order against an RFQ through independent distribution; availability and current pricing confirmed at quote time.
Panel fit and integration
Dimensions: 248 mm high, 184 mm wide, 110 mm deep. That 184 mm width for a 4-pole frame is standard for this class — verify your DIN-rail or mounting-plate spacing before cutting gland plates. The 110 mm depth leaves room behind a 200 mm deep enclosure for wiring and finger-duct. Maximum power loss is 96 W. In a sealed, non-ventilated enclosure that heat adds up — account for it in your thermal budget, especially if the breaker is grouped with other high-current devices.