What this 40 A MCCB covers
The Siemens SENTRON 3VA2140-8HM42-0AA0 is a 4-pole molded case circuit breaker (MCCB) sized for line protection at 40 A continuous current, flat across the ambient range from 40 °C to 70 °C — no derating needed up to that full 70 °C operating maximum. That 40 A rating holds at every temperature step in the spec, so you can size this into a warm panel without recalculating. Breaking capacity runs 440 kA at 240 V, 330 kA at 415 V and 440 V, 220 kA at 500 V, and 52.5 kA at 690 V — those numbers cover high-fault utility feeds and transformer secondaries. The ETU330 electronic trip unit handles the overcurrent release; N-conductor protection is adjustable OFF or 100%, and ground-fault monitoring uses summation current on L+N. At 86 mm deep, 140 mm wide, and 181 mm tall, it fits standard SENTRON 3VA panel cutouts. Front IP40 keeps it sealed against tools and fingers in a closed enclosure.
Integration and mounting
Four-pole MCCB, 140 mm wide — mounts into a standard SENTRON 3VA panel base or DIN-rail adapter. Front IP40 means it's touch-safe once the panel door is closed. No undervoltage release, no voltage trigger, no communication module on this variant; it's a straight line-protection breaker with the ETU330 trip unit doing the decision-making. Power loss is 1.2 W maximum — negligible for thermal budgeting inside a crowded enclosure. Storage range -40 °C to 80 °C covers warehouse extremes.