What this MCCB delivers on the line
The Siemens SENTRON 3VA2450-5MN32-0JA0 is a 3-pole molded case circuit breaker (MCCB) rated for a continuous current Iu of 500 A, with the ETU350M electronic overcurrent release handling the protection curve. Per the datasheet, it carries a breaking capacity of 187 kA at 240 V, 121 kA at 415 V and 440 V, 75.6 kA at 500 V, and 17 kA at 690 V — so the SCCR headroom is substantial for most industrial distribution panels. The motor protection designation means it includes phase failure detection and a voltage trigger, making it suited for motor branch circuits where loss-of-phase protection is required.
Thermal derating and panel fit
At 40 °C, 45 °C, and 50 °C the breaker holds its full 500 A rating. Derating begins at 55 °C (495 A), dropping to 480 A at 70 °C. The maximum power loss is 99 W, which matters for enclosure heat rise calculations — a panel with multiple breakers at full load needs ventilation or forced cooling. Dimensions are 248 mm height, 138 mm width, and 110 mm depth, so it fits standard MCCB mounting footprints. The operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C.
Trip unit and auxiliary options
The ETU350M release is the overcurrent protection brain — it's an electronic trip unit with adjustable settings (the specific curve parameters are in the full datasheet). This variant ships with a shunt trip (STL) as the auxiliary release design, but no undervoltage release, no auxiliary contact version, and no ground fault monitoring. The integrated auxiliary trip order code is 3VA9688-0BL32; the supplied basic switch is 3VA2450-5MN32-0AA0. Latching endurance is rated at 15,000 operations.