Siemens 3VM1225-4EE32-0AA0 — SENTRON MCCB, 250 A, Line Protection
The Siemens 3VM1225-4EE32-0AA0 is a SENTRON molded case circuit breaker (MCCB) rated for line protection, with a TM220 thermal-magnetic overcurrent release. It carries a maximum of 2 500 A and delivers a breaking capacity of 121 kA at 240 V AC, 76 kA at 415 V AC, 53 kA at 440 V AC, and 17 kA at 500 V AC — figures that tell you the fault current it can safely interrupt at each voltage level without upstream cascading. Rated insulation voltage is 800 V, operating voltage up to 690 V AC. Current rating holds at 250 A up to 50 °C ambient, then derates to 243.3 A at 55 °C, 236.5 A at 60 °C, 229.8 A at 65 °C, and 223 A at 70 °C. That derating curve is the one to check if this breaker sits in a warm enclosure — the headline 250 A is only valid below 55 °C. Three-pole design, no undervoltage release, no ground-fault monitoring, no communication function. IP40 on the front means it's protected against tools and small wires entering from the front face — standard for panel-mount gear, but not rated for washdown or outdoor exposure. Dimensions: 70 mm deep, 105 mm wide, 158 mm high.
Integration & Panel Fit
Operating temperature range is -25 °C to 70 °C; storage range -40 °C to 80 °C. Maximum power loss is 57 W — factor that into enclosure thermal calculations if the panel is densely packed.