SENTRON 3VA1125-4EF32-0JH0 — 25 A MCCB with 121 kA interrupting capacity
The Siemens SENTRON 3VA1125-4EF32-0JH0 is a 3-pole molded case circuit breaker (MCCB) designed for line protection in distribution panels. It carries a rated current of 25 A at 40 °C and delivers a 121 kA interrupting capacity at 240 VAC — enough to handle high-fault utility feeds without cascading upstream. At 415 V it still breaks 75.6 kA, and at 690 V it holds 11.9 kA, so this breaker handles the full range of industrial supply voltages common in North American and European panels. The rated insulation voltage is 800 V, giving headroom for 480/600 V systems. The breaker ships with a shunt trip (STL) release and a 2-auxiliary-switch plus 1-trip-alarm-switch HQ configuration — useful for remote tripping and status feedback to a PLC or SCADA system.
Thermal derating and panel integration
The 25 A rating holds flat from 40 °C to 50 °C, then drops to 24 A at 55–60 °C and 23 A at 65–70 °C. If this breaker sits in a warm enclosure near other heat sources, plan for the 23 A ceiling at 70 °C — the full 25 A is only available below 50 °C ambient. Dimensions are 70 mm deep, 76.2 mm wide, and 130 mm tall, fitting standard 3-pole MCCB panel cutouts. Maximum power loss is 8.5 W, manageable in a ventilated section.