Siemens 3VA1332-6EF32-0DG0 — 320 A SENTRON MCCB with Undervoltage Release
Rated insulation voltage is 800 V, and the thermal current rating holds at 320 A through 50 °C, then derates to 313 A at 55 °C, 306 A at 60 °C, 299 A at 65 °C, and 292 A at 70 °C. That derating curve is the one to check if the breaker sits near other heat sources in a packed enclosure. Built-in undervoltage release (UVR) and a 1 auxiliary switch plus 1 trip alarm switch give the panel builder a clean way to signal trip state and coordinate with upstream controls without adding external relays.
Physical Fit and Panel Integration
Dimensions: 248 mm high, 138 mm wide, 110 mm deep. That 110 mm depth is the dimension to watch when the breaker mounts in a shallow backpanel or against a gland plate — it fits standard SENTRON 3VA drawout and fixed-mount footprints, so a panel kitted for a 3VA frame will accept this unit without re-drilling. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C. Maximum power loss is 82.6 W at full load — factor that into the enclosure thermal budget if the panel is sealed or has limited convection.