What it is and what it does
The Siemens SENTRON 3VA2450-5MN32-0HA0 is a 3-pole molded case circuit breaker (MCCB) built for motor protection, with a rated continuous current Iu of 500 A and an ETU350M electronic overcurrent release. The ETU350M trip unit provides phase failure detection and a shunt trip (STL) for remote tripping — no undervoltage release, no auxiliary contacts built in. Breaking capacity ranges from 187 kA at 240 V down to 17 kA at 690 V, with 121 kA at 415 V and 440 V, and 75.6 kA at 500 V — so it handles high-fault utility feeds and large motor branch circuits without upstream fusing in most installations.
Thermal performance and panel integration
Rated 500 A from 40 °C through 50 °C, then derates linearly to 480 A at 70 °C — typical for a panel with multiple breakers stacked together; plan your enclosure cooling if the ambient stays above 50 °C. Dimensions: 248 mm high, 138 mm wide, 110 mm deep. The 138 mm width is a 3-pole frame; it fits standard SENTRON 3VA switchboard cutouts and DIN-rail adapters. Maximum power loss is 99 W — that's the heat the breaker dumps into the enclosure at full load; factor it into your thermal budget if the panel is sealed.
Lifecycle and sourcing
The basic switch element is order code 3VA2450-5MN32-0AA0; the integrated auxiliary trip is 3VA9688-0BL30 — both are serviceable spares if you need to replace just the trip unit or the switch mechanism.