What this 4-pole 250 A MCCB carries
The Siemens SENTRON 3VA2225-8HM42-0AA0 is a 4-pole molded case circuit breaker rated 250 A continuous at 40 °C through 50 °C, with a 440 kA interrupting capacity at 240 V — that is the headline number for fault-clearing on a high-capacity distribution bus, not a motor-starting duty. The ETU330 electronic trip unit gives you adjustable N-conductor protection (OFF, 50%, 100%) and a summation ground-fault monitoring version that sums L + N conductor current, so it handles both line protection and residual current detection in one frame.
Breaking capacity across voltage levels
At 415 V and 440 V it still holds 330 kA; at 500 V it drops to 220 kA; at 690 V it is 52.5 kA. That means this breaker is sized for a main or feeder position in a 240 V to 480 V distribution panel where fault current is high — think a transformer secondary or a large motor control center bus. The 250 A frame with those interrupting ratings is not a branch device; it is a main or tie breaker.
Thermal derating and physical fit
The 250 A rating holds flat to 50 °C; above that it derates to 241 A at 55 °C, 232 A at 60 °C, 222 A at 65 °C, and 213 A at 70 °C. That thermal curve matters if this breaker lives in a non-air-conditioned enclosure or near heat-generating buswork. Dimensions are 140 mm wide by 181 mm tall by 86 mm deep — a standard 4-pole MCCB footprint for SENTRON 3VA frames. Front face carries IP40 protection, so it is fine in a clean indoor panel but not washdown.