What this MCCB is and what the ratings mean
The Siemens SENTRON 3VA1140-6EF46-0AA0 is a 4-pole molded case circuit breaker (MCCB) rated for 40 A continuous current at 40 °C, with a TM240 thermal-magnetic release for line protection. The 220 kA interrupting rating at 240 V means it can safely clear a fault of that magnitude without upstream coordination issues — critical for high-fault-capacity service entrances or transformer secondaries. At 415 V it still holds 154 kA, and at 440 V it's rated 121 kA, so it handles industrial distribution panels where fault currents are substantial. The 800 V rated insulation voltage (Ui) confirms it's suitable for 480 V and 600 V class systems.
Thermal derating and panel fit
The 40 A rating holds steady up to 50 °C ambient, then drops to 39 A at 55 °C and 37 A at 70 °C. In a warm enclosure — say a steel panel with multiple breakers — that derating curve matters for sizing the branch circuit. The 70 mm depth and 101.6 mm width fit standard MCCB panel footprints; IP40 on the front means it's protected against tools and wires but not washdown, so keep it inside the enclosure.