The Siemens SENTRON 3VA1225-5EF32-0JC0 is a 3-pole molded case circuit breaker (MCCB) rated for line protection, carrying a rated continuous current Iu of 250 A and a rated insulation voltage Ui of 800 V. Its breaking capacity reaches 187 kA at 240 V, 121 kA at 415 V, 36 kA at 440 V, and 17 kA at 690 V — figures that define the fault-current headroom for the downstream distribution board.
Thermal derating and fit
The TM240 thermal-magnetic release holds the full 250 A from 40 °C through 50 °C, then derates to 243.3 A at 55 °C, 236.5 A at 60 °C, 229 A at 65 °C, and 223 A at 70 °C. In a panel that sees 55 °C ambient, the breaker is good for 243.3 A continuous — not the full 250 A. The operating temperature range is -25 °C to 70 °C; storage from -40 °C to 80 °C. Dimensions are 105 mm wide, 158 mm high, 70 mm deep — fits standard SENTRON 3VA panel cutouts. IP40 on the front; no trip indicator, no undervoltage release, no ground-fault monitoring, no communication module. Auxiliary contact version is 2 auxiliary switches HQ; the integrated shunt trip (STL) is designed with auxiliary trip order code 3VA9688-0BL32.