The Siemens SENTRON 3VM1225-4EE46-0AA2 is a 4-pole molded case circuit breaker (MCCB) rated for line protection, carrying a continuous current Iu of 250 A. The TM220 thermal-magnetic release provides adjustable overload (Ir max. 250 A) and short-circuit (Ii max. 2,500 A) protection, making it a direct fit for main feeder or large branch-circuit protection in 400 V class distribution panels.
Breaking capacity across voltage levels
This MCCB delivers 121 kA at 240 V, 76 kA at 415 V, 53 kA at 440 V, and 17 kA at 500 V. The steep drop above 440 V means the 500 V rating governs high-impedance fault scenarios on 480 V wye systems — verify the available fault current at the point of installation against the 17 kA figure before committing the BOM line.
Thermal derating and panel integration
Rated continuous current holds at 250 A from 40 °C through 50 °C ambient, then derates linearly to 223 A at 70 °C. The 70 mm depth and 138 mm width fit standard SENTRON mounting footprints; IP40 on the front means the breaker is protected against solid objects over 1 mm but not against water ingress — suitable for indoor panel mounting where the enclosure provides the environmental seal.