Siemens 3VA1225-5EF42-0AE0 — SENTRON 250 A MCCB, 4-Pole, TM240
The Siemens 3VA1225-5EF42-0AE0 is a SENTRON molded case circuit breaker (MCCB) designed for line protection, rated 250 A at 40 °C with a 4-pole configuration and a TM240 thermal-magnetic overcurrent release. Breaking capacity reaches 187 kA at 240 V, 121 kA at 415 V, 75.6 kA at 440 V, 30 kA at 500 V, and 17 kA at 690 V — high enough for most industrial main-feed and distribution applications where fault currents are substantial. The 250 A rating holds from 40 °C through 50 °C, then derates to 243 A at 55 °C, 237 A at 60 °C, 230 A at 65 °C, and 223 A at 70 °C — useful when the breaker sits in a warm enclosure or near other heat sources.