What this 500 A SENTRON MCCB does on the line
The Siemens 3VA2450-5MN32-0BL0 is a SENTRON molded case circuit breaker designed specifically for motor protection — it carries phase failure detection and an undervoltage release, so it's wired into the motor feeder, not a general distribution bus. Rated 500 A continuous at 40 °C, it holds that same 500 A all the way up to 50 °C, then derates to 480 A at 70 °C. That thermal curve means you don't lose headroom in a warm enclosure as long as ambient stays under 50 °C. Three-pole construction, 248 mm tall by 138 mm wide by 110 mm deep — standard SENTRON 3VA frame footprint. The auxiliary switch complement is two auxiliary switches plus one trip alarm and one electrical alarm switch, all HQ type, so you get both status and fault signalling back to the PLC without adding external relays.
Short-circuit withstand — where it interrupts and where it doesn't
The interrupting ratings climb fast as voltage drops: 187 kA at 240 V, 121 kA at 415 V and 440 V, 75.6 kA at 500 V, then falls to 9 kA at 690 V. That 9 kA at 690 V is the weak point — if your system fault current at 690 V exceeds that, this breaker won't clear it. At 240 V though, 187 kA covers nearly any industrial service entrance. The limited-to-1-second rating is 6 kA, which governs the short-time delay setting for selective coordination downstream.
Panel fit and wiring notes
Mounts in the standard SENTRON 3VA frame cutout — 138 mm wide means it occupies three 45 mm module spaces on a DIN rail or bolts directly to a mounting plate. The undervoltage release (UVR) is built in, so verify your control voltage matches the release rating before energizing; if the UVR coil sees a dropout, the breaker trips instantly. Phase failure detection is internal — no external phase-loss relay needed for motor protection.