MCCB with a real derating curve
The Siemens 3VA1140-6EF36-0AC0 is a SENTRON 3-pole molded case circuit breaker rated for 40 A continuous at 40 °C ambient, with a TM240 thermal-magnetic overcurrent release. The breaking capacity is 220 kA at 240 V, stepping down to 154 kA at 415 V and 121 kA at 440 V — still 17 kA at 690 V, which covers most industrial distribution voltages. The temperature derating is non-trivial: holds 40 A from 40 °C through 50 °C, drops to 39 A at 55 °C and 60 °C, then 38 A at 65 °C, and 37 A at 70 °C.
Panel fit and build
The 3-pole footprint is standard for SENTRON 3VA MCCBs — fits existing panel cutouts and busbar layouts designed for the series. Comes factory-fitted with two auxiliary switches HQ.
