What the interrupting ratings mean for your panel
The Siemens SENTRON 3VA1140-4EF36-0CA0 is a 3-pole molded case circuit breaker rated 40 A continuous at 40 °C, sized for line protection in a distribution panel. Its interrupting capacity hits 121 kA at 240 V, 75.6 kA at 415 V, and 52.5 kA at 440 V — numbers that govern whether this breaker clears a fault without upstream damage. At 500 V and 690 V the rating drops to 11.9 kA, so confirm the available fault current at your system voltage before committing the BOM line. The TM240 thermal-magnetic release provides fixed thermal and magnetic trip settings. The breaker also includes an undervoltage release (UVR) — if control voltage drops, the UVR trips the breaker, which is useful for safety circuits or coordinated shutdown sequences. No communication function or ground-fault monitoring is built in, so keep that in mind if the spec calls for remote trip indication or GF protection.
Thermal derating and panel integration
The 40 A rating holds from 40 °C through 50 °C. At 55 °C it derates to 39 A, at 65 °C to 38 A, and at 70 °C to 37 A. If the breaker sits in a sealed enclosure or near other heat sources, factor that 3 A drop at the top end. Maximum power loss is 13.3 W — negligible for most panels but worth a glance in a densely packed cabinet. Dimensions are 76.2 mm wide, 130 mm high, 70 mm deep. The 3-pole width matches the standard SENTRON 3VA footprint, so it drops into a panel pre-drilled for the series without rework. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C.