The four-pole design with an ETU350 electronic overcurrent release makes it a line-protection breaker for distribution panels feeding heavy loads like large motor control centers or transformer secondaries. Interrupting capacity is the headline number here: 187 kA at 240 V, 121 kA at 415/440 V, 75.6 kA at 500 V, and 9 kA at 690 V.
At 110 mm deep, 184 mm wide, and 248 mm tall, this breaker fits standard SENTRON 3VA switchboard mounting patterns. The 400 A frame is physically larger than the 250 A frame in the same series — verify busbar spacing and lug kit compatibility if replacing a smaller 3VA unit. In a sealed panel with multiple breakers at full load, factor that into the thermal budget.