What this MCCB carries
The Siemens SENTRON 3VA2450-5MN32-0DC0 is a 3-pole molded case circuit breaker (MCCB) designed for motor protection, rated 500 A continuously at 40 °C ambient. That 500 A holds flat through 50 °C — only drops to 495 A at 55 °C and 480 A at 70 °C, so it doesn't derate hard in a warm panel. Interrupting capacity at 240 V is 187 kA; at 415 V and 440 V it's 121 kA; at 500 V it's 75.6 kA; at 690 V it's 9 kA. The 187 kA at 240 V means it can safely clear a fault on a high-capacity transformer secondary without upstream fuses having to help — useful for main or large feeder duty. It includes an undervoltage release (UVR) and two HQ auxiliary switches, plus phase failure detection. Power loss at full load runs 101.5 W max — factor that into enclosure thermal calculations.
Panel fit and mounting
Dimensions: 248 mm high, 138 mm wide, 110 mm deep. The 138 mm width is the standard 3-pole MCCB footprint for this SENTRON frame — it occupies three 45 mm-wide modular spaces on a DIN rail or bolts directly to a mounting plate. Depth of 110 mm includes the handle and terminals; leave clearance for cable bending radius and the UVR coil projection on the left side.
Time-current characteristics
The short-time withstand rating is 6 kA limited to 1 s — that's the thermal let-through the breaker can handle during a delayed trip coordination interval. The trip unit's minimum response time is 4 s, maximum 13 s, which puts it in the 'selective' band for downstream coordination with smaller MCCBs or fused switches.
Environmental limits
Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C. The storage low end matters if this sits in an unheated warehouse before installation — it's fine down to -40 °C, but don't energize below -25 °C.