The Siemens SENTRON 3VA2125-5KP46-0AA0 is a 4-pole molded case circuit breaker (MCCB) rated for 25 A continuous current, fitted with an ETU850 electronic trip unit. It is designed for line protection in distribution panels and motor control centers, with a breaking capacity of 187 kA at 240 V AC, derating to 121 kA at 415 V and 3.7 kA at 690 V. The ETU850 provides adjustable overload and short-circuit protection curves, plus communication capability for integration into higher-level monitoring systems.
Breaking capacity and trip unit
The 187 kA interrupting rating at 240 V means this MCCB can safely clear a fault current up to that level without rupturing — critical for high-fault installations close to the transformer secondary. At 415 V the rating is 121 kA, and at 690 V it drops to 3.7 kA, reflecting the physics of arc extinction at higher voltages. The ETU850 electronic trip unit allows field-adjustable long-time, short-time, and instantaneous pickup settings, plus ground-fault detection when paired with an external sensor (this unit ships without the ground-fault monitoring module).
Thermal derating and ambient limits
The 25 A continuous rating holds flat across the entire operating ambient range from -25 °C to 70 °C — no derating needed up to the maximum. This simplifies panel design: you can populate adjacent breakers at full rating without calculating temperature de-rates, provided the enclosure ambient stays within that band. Storage limits are -40 °C to 80 °C, which governs handling and warehousing, not service.
Physical integration
Dimensions are 181 mm height, 140 mm width, 86 mm depth. Front-face protection is IP40.