The Siemens SENTRON 3VM1340-4EE42-0AA0 is a 4-pole molded case circuit breaker rated for 400 A continuous at 40 °C, with a TM220 thermal-magnetic release designed for line protection. It carries an interrupting capacity of 121 kA at 240 V, 76 kA at 415 V and 440 V, and 53 kA at 500 V — figures that define the fault-clearing capability at the point of installation and drive the upstream SCCR coordination study.
Thermal Derating and Continuous Current
The 400 A rating holds flat from 40 °C through 50 °C, then derates to 392 A at 55 °C, 384 A at 60 °C, 376 A at 65 °C, and 367 A at 70 °C. For a panel that runs warm — say, 55 °C ambient inside the enclosure — the breaker still carries 392 A continuous, which is the figure to use for the load schedule, not the 40 °C nameplate.
The breaker measures 248 mm high, 184 mm wide, and 110 mm deep. These are the envelope dimensions for cutout planning and bus-bar spacing in the panel.