The Siemens SENTRON 3VA1140-6EF36-0AD0 is a 3-pole molded case circuit breaker rated for 40 A continuous current (Iu) with a TM240 thermal-magnetic overcurrent release. Its breaking capacity reaches 220 kA at 240 V, 154 kA at 415 V, and 121 kA at 440 V — figures that place it in the high-interrupting category for industrial distribution panels where fault current levels are substantial. The TM240 release means the thermal element is fixed at 40 A; no field adjustment of the continuous rating. The 70 mm depth and 76.2 mm width fit standard SENTRON panel footprints, and the IP40 front protection keeps dust out of the enclosure face. Three auxiliary switches (HQ type) are integrated for status feedback to a PLC or annunciator panel.
Breaking capacity and selectivity
At 415 V the 154 kA interrupting rating gives headroom for high-fault installations — common in industrial mains where transformer impedance is low. The 690 V rating drops to 17 kA, which still covers most motor branch circuits at that voltage. For selectivity studies, the 40 A frame coordinates downstream with smaller MCCBs or MCBs; the 800 V rated insulation voltage (Ui) supports 690 V systems with margin.
Thermal derating and ambient limits
The breaker carries its full 40 A from 40 °C through 50 °C ambient. Above that it derates: 38.4 A at 55 °C, 37.6 A at 60 °C, 36.8 A at 65 °C, and 36 A at 70 °C. If the panel runs hot — near a drive or transformer — factor the derating into the load calculation. Operating range is -25 °C to 70 °C; storage from -40 °C to 80 °C.