What this MCCB brings to the panel
The SENTRON 3VA1225-5EF42-0HC0 is a 4-pole molded case circuit breaker rated 250 A continuous at 40 °C, with an interrupting capacity of 187 kA at 240 V — that's the headline number for fault clearing in low-voltage distribution. At 415 V it still holds 121 kA, and at 690 V it's 17 kA, so the same frame covers both 400 V and 480 V systems without swapping breakers for the voltage class. Rated insulation voltage is 800 V, and the thermal derating curve is flat from 40 °C through 50 °C (still 250 A), then drops to 243 A at 55 °C and 223 A at 70 °C. That means in a warm enclosure you lose less than 11% capacity up to 65 °C, which is better than many older frames that start derating at 40 °C. This is a line-protection design (not motor-protection), so it's sized for feeder or main breaker duty in a distribution panel, not for direct motor overload protection. The built-in shunt trip release lets you remotely trip the breaker from a safety circuit or emergency-stop chain without adding an external undervoltage release.
Panel fit and dimensions
The breaker measures 140 mm wide by 158 mm tall by 70 mm deep. It fits the same mounting hole pattern as other SENTRON 3VA frames.
What the ratings mean on site
187 kA at 240 V is a very high interrupting rating — it means this breaker can safely clear a fault on the secondary side of a large transformer or in a high-capacity busway without the arc flash energy escalating. That 187 kA figure is the short-circuit current rating (SCCR) at that voltage; the breaker itself is the protection device, not a downstream component needing a current-limiting fuse upstream. Maximum power loss is 57 W, which matters for enclosure thermal management. In a sealed panel with multiple breakers, that's about the heat of a small incandescent lamp per unit — account for it in the ventilation or cooling calculation.