SENTRON 3VM1450-4EE42-0AA0 — 500 A MCCB with TM220 Release
The Siemens SENTRON 3VM1450-4EE42-0AA0 is a 4-pole molded case circuit breaker rated for 500 A continuous current, fitted with a TM220 thermal-magnetic overcurrent release. The TM220 designation means the thermal pickup (Ir) is adjustable up to 500 A, and the magnetic short-circuit pickup (Ii) is fixed at 5000 A — ten times the rated current — providing instantaneous trip on high fault currents without intentional delay. Breaking capacity varies by system voltage: 121 kA at 240 V, 76 kA at both 415 V and 440 V, and 53 kA at 500 V. These are the maximum short-circuit currents the breaker can safely interrupt at each voltage level — critical for verifying SCCR compliance with the upstream transformer or generator fault contribution.
Thermal Derating and Panel Integration
The 500 A rating holds from 40 °C through 50 °C ambient. Above that, derate linearly: 488 A at 55 °C, 476 A at 60 °C, 464 A at 65 °C, and 452 A at 70 °C. For a panel with multiple breakers ganged in a confined enclosure, use the 60 °C column as the practical design limit unless forced-air ventilation is verified. Dimensions are 184 mm wide, 248 mm high, 110 mm deep — a 4-pole frame that occupies roughly 7.2 inches of DIN-rail width. The IP40 front protection rating means the breaker face is protected against tools and wires >1 mm, but the enclosure must handle the rest of the IP rating for the overall panel. Maximum power dissipation is 122.7 W at full rated current. Account for this in the enclosure thermal budget — at 500 A continuous, that heat must be removed to stay within the derating curve above.
Electrical Ratings and Coordination
Rated insulation voltage is 690 V, giving headroom for 480/600 V class systems. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C. This is a line-protection version with no communication function, no ground-fault monitoring, and no N-conductor protection. It is a straight thermal-magnetic breaker for branch-circuit or feeder protection in distribution panels.