What this MCCB is and what it does
The Siemens 3VA2025-8KQ46-0AA0 is a SENTRON molded case circuit breaker (MCCB) designed for line protection in industrial power distribution. It carries a continuous rated current of 25 A across the full ambient temperature range from 40 °C to 70 °C, with no derating needed — the rating holds at 25 A all the way up to 70 °C. That's a solid thermal margin for a panel that runs hot.
Breaking capacity — what the numbers mean for your panel
This MCCB delivers 440 kA interrupting capacity at 240 V, 330 kA at 415 V and 440 V, 220 kA at 500 V, and 52.5 kA at 690 V. Those are high values for a 25 A frame — the breaker can clear a massive fault without rupturing, which is what you need when the available fault current at the panel is high. The 52.5 kA at 690 V is notably lower but still covers most industrial 690 V distribution. The rated insulation voltage is 800 V, so the breaker is built to handle the voltage stress of a 690 V system with margin. The operating temperature range of -25 °C to 70 °C and storage range of -40 °C to 80 °C cover most indoor and outdoor enclosure conditions.
Integration and mounting
The breaker measures 140 mm wide, 181 mm high, and 86 mm deep. That 86 mm depth is the key dimension for panel clearance — it fits standard distribution board depths without sticking out past the gland plate. The width of 140 mm is typical for a 4-pole MCCB in this frame size; check your DIN-rail or mounting-plate layout for the 4-module footprint. It includes a communication function and ground-fault monitoring via summation current formation of L + N conductors, which means you can integrate it into a monitoring system without an external ground-fault relay. The maximum power loss is only 0.5 W, so heat buildup in a sealed enclosure is negligible.
Sourcing and lifecycle
The lifecycle stage is listed as current, meaning Siemens still manufactures this exact order code. No end-of-life notice, no last-time-buy clock. For a BOM freeze or a line-down replacement, this is a straightforward catalog item — sourced and quoted to order against an RFQ through independent distribution, with availability and current pricing confirmed at quote time.