Line protection breaker with thermal-magnetic trip
The Siemens SENTRON 3VM1450-5ED32-0AA0 is a 3-pole molded case circuit breaker (MCCB) rated for line protection, carrying 500 A continuously at 40 °C ambient without derating. The TM210 thermal-magnetic trip unit handles overload and short-circuit protection in a single package — no separate relay or CT needed for most distribution and light motor feeder applications. Breaking capacity reaches 187 kA at 240 V AC, 121 kA at 415 V and 440 V, and 76 kA at 500 V — figures that cover most industrial service-entrance and sub-distribution fault levels. Rated insulation voltage is 800 V, with a maximum operational voltage of 690 V AC and 500 V DC. The frame is sized at 138 mm wide, 248 mm tall, and 110 mm deep — a standard SENTRON 3VM footprint that fits existing panel cutouts and busbar arrangements. Front-side protection is IP40, suitable for enclosed switchboards where tools are required to access live parts.
Current derating and thermal management
Rated current holds flat at 500 A from 40 °C through 50 °C, then steps down linearly: 488 A at 55 °C, 476 A at 60 °C, 464 A at 65 °C, and 452 A at 70 °C. Maximum power loss is 123 W — a figure to account for in enclosed panel heat budgets, particularly when multiple breakers are ganged in a single section. Operating ambient range spans -25 °C to 70 °C; storage range extends from -40 °C to 80 °C. The 70 °C operating ceiling matches the fully derated current at that temperature, so the breaker can be deployed in warm machine compartments or outdoor enclosures without additional ventilation beyond what the heat load requires.
Integration notes
Mounts on a standard DIN rail or directly to a panel backplate via the four corner fixing points — the 138 mm width matches the 3VM frame spacing used across the SENTRON line, so busbar connectors and phase barriers transfer from other 3VM breakers in the same panel. No undervoltage release, no shunt trip, and no communication module are fitted on this variant; those are added as external accessories if needed. The TM210 trip unit is field-replaceable but factory-set — no dial-adjustable thermal or magnetic settings on this version. For applications requiring adjustable long-time and short-time pickup, the electronic trip variants in the 3VA series would be the next step up.