Rated continuous current and breaking capacity
The Siemens SENTRON 3VA1340-5GF42-0AA0 is a 4-pole molded case circuit breaker rated for 400 A continuous current at 40 °C, with the TM240 thermal-magnetic overcurrent release. Its interrupting capacity reaches 187 kA at 240 V AC, 121 kA at 415/440 V, 75.6 kA at 500 V, and 11.9 kA at 690 V — so it handles high-fault utility feeds and transformer secondaries without cascading upstream.
Thermal derating and ambient limits
The breaker holds full 400 A rating up to 50 °C ambient. Above that it derates linearly: 392 A at 55 °C, 384 A at 60 °C, 376 A at 65 °C, and 367 A at 70 °C. Operating ambient range is -25 °C to +70 °C; storage range is -40 °C to +80 °C. For a panel builder, this means the breaker can sit in a warm enclosure without forced cooling as long as the load current stays under the derated curve.
Physical integration
Dimensions are 248 mm high, 184 mm wide, and 110 mm deep. The 4-pole footprint fits standard panel-mount cutouts for SENTRON 3VA frames. No undervoltage release, no communication module, and no ground-fault monitoring on this variant — it is a straight line-protection breaker with a TM240 release.