SENTRON 3VA1125-3EF32-0AH0 — 25 A MCCB, line protection, current production
The Siemens 3VA1125-3EF32-0AH0 is a SENTRON molded case circuit breaker (MCCB) for line protection, rated 25 A continuous current (Iu) at 40 °C, with a 3-pole configuration and a TM240 thermal-magnetic overcurrent release. Breaking capacity reaches 75.6 kA at 240 V, 52.5 kA at 415 V, 32 kA at 440 V, and 10.5 kA at 690 V — figures that tell you it handles high-fault utility feeds or transformer secondaries without cascading upstream.
Thermal derating and auxiliary contacts
The 25 A rating holds flat from 40 °C to 50 °C, then steps down to 24 A at 55 °C, 23.5 A at 60 °C, 23 A at 65 °C, and 22.5 A at 70 °C. That derating curve is what you check when the breaker sits near other heat sources in a crowded enclosure — at 60 °C ambient you lose 1.5 A of headroom.