What it is and what it does
The Siemens 3VA1025-3ED32-0KH0 is a SENTRON molded case circuit breaker (MCCB) designed for line protection in distribution panels. Rated 25 A at 40 °C, it carries that current continuously through 50 °C, then derates to 24 A at 55–60 °C and 23 A at 65–70 °C — a thermal curve you need for panel ambient planning, not just the headline number. Breaking capacity is the real selector here: 75.6 kA at 240 V, 52.5 kA at 415 V, 32 kA at 440 V, and 7.5 kA at both 500 V and 690 V. That 7.5 kA floor at 690 V tells you this breaker is sized for 400 V-class systems where fault current stays under 50 kA — not for high-fault 690 V installations.
Panel fit and integration
Dimensions are 70 mm deep, 76.2 mm wide, and 130 mm tall — a compact 3-pole footprint that fits standard MCCB panel cutouts. The 8.5 W maximum power loss at rated load factors into enclosure thermal calculations; if you're packing multiple breakers in a sealed cabinet, that heat adds up. Comes with a shunt trip (STL) auxiliary release and space for 2 auxiliary switches plus 1 trip alarm switch HQ. No undervoltage release, no ground-fault monitoring, no communication module — this is a basic line-protection breaker with trip indication and voltage-trigger capability.