Product identity and key ratings
The Siemens SENTRON 3VA1340-7EF32-0AA0 is a 3-pole molded case circuit breaker (MCCB) designed for line protection, carrying a rated current of 400 A at 40 °C and a breaking capacity of 440 kA at 240 V. The overcurrent release is a TM240 thermal-magnetic unit, which means it provides both overload (thermal) and short-circuit (magnetic) protection without electronic adjustment — a fixed-trip design suited for standard distribution panels where qualification documentation must match a single, traceable part number. Rated insulation voltage is 800 V, and the unit is IP40 on the front, so it is suitable for installation inside a panel enclosure that provides the environmental seal; it is not rated for washdown or outdoor exposure without a secondary cabinet.
Current derating and thermal management
The 400 A rating holds steady up to 50 °C ambient; above that it derates linearly to 367 A at 70 °C. Maximum power loss is 92.1 W, so panel ventilation and inter-device spacing must accommodate that heat load — particularly in a densely packed switchboard.
Breaking capacity across voltage levels
The 3VA1340-7EF32-0AA0 delivers 440 kA at 240 V, 242 kA at 415 V and 440 V, 154 kA at 500 V, and 17 kA at 690 V. The steep drop at 690 V means this breaker is sized for low-voltage distribution up to 500 V; at 690 V the fault current must be verified against the installation's available fault current.