SENTRON 3VA2450-7MN32-0AF0 — 500 A MCCB for Motor Protection
The Siemens SENTRON 3VA2450-7MN32-0AF0 is a 3-pole molded case circuit breaker (MCCB) rated for motor protection duty, carrying 500 A continuously at 40 °C ambient. That 500 A holds flat through 50 °C, then derates to 495 A at 55 °C and 480 A at 70 °C — so in a warm enclosure you still have nearly full rating. Breaking capacity runs 330 kA at 240 V, 242 kA at 415/440 V, 187 kA at 500 V, and 15.3 kA at 690 V, which covers most industrial fault-current scenarios without an upstream current-limiting fuse.
What the Ratings Mean for Fit
The 500 A frame is sized for large motor loads — think 250–350 kW induction motors on 400 V three-phase, or a group of smaller motors on a common feeder. The motor protection design means the trip curve is shaped to handle inrush without nuisance tripping while still clearing a locked-rotor fault. Phase failure detection is built in, so the breaker will trip on loss of one phase — critical for preventing single-phasing damage on a motor. The auxiliary switch configuration includes 1 auxiliary switch plus 1 trip alarm switch HQ. That gives you one N.O./N.C. set for status feedback and a separate alarm contact that changes state only on a trip event — useful for remote annunciation in a PLC or SCADA system. Power loss is 99 W maximum. In a sealed panel with multiple breakers, that heat adds up — factor it into your thermal budget if the enclosure is IP-rated and unventilated.
Integration and Mounting
Dimensions are 248 mm high, 138 mm wide, 110 mm deep — a standard MCCB footprint for a 500 A frame. It mounts on a DIN rail or direct-panel via the rear slots. The 3-pole design with no undervoltage release and no communication module keeps it a straightforward thermal-magnetic or electronic-trip breaker; wire it as a standalone motor-protection device.