What it is and what it does
The Siemens 3VA2140-8HK42-0AA0 is a SENTRON molded case circuit breaker (MCCB) with a 40 A continuous rating across the full 40 °C to 70 °C ambient range — no derating needed up to that ceiling. Four poles, electronic ETU340 trip unit, designed for line protection in distribution panels. Breaking capacity is the headline figure here: 440 kA at 240 V, 330 kA at 415/440 V, 220 kA at 500 V, and 52.5 kA at 690 V. That puts it in the high-interrupting class — sized for large transformer secondaries or bus-tie applications where fault current runs high. Insulation voltage rated 800 V, so it handles 690 V line-to-line comfortably.
Panel fit and deployment context
Dimensions: 86 mm deep, 140 mm wide, 181 mm tall. Front face carries IP40 protection — suitable for enclosed distribution boards where splash is not expected. No undervoltage release, no communication function, no ground-fault monitoring on this variant; it is a straight line-protection breaker with the ETU340 electronic trip. Trip indicator not fitted, so fault indication relies on the panel's own annunciation.