What this MCCB is and what it does
The Siemens 3VA2140-8HK32-0AA0 is a SENTRON molded case circuit breaker (MCCB) designed for line protection — meaning it sits at the feeder or distribution point to protect cables and downstream equipment from overloads and short circuits. It's a 3-pole unit rated for 40 A continuous current across the full ambient range from -25 °C to 70 °C, so no derating headache in a warm enclosure. The ETU340 electronic trip unit gives you adjustable overload and short-circuit protection curves, not a fixed thermal-magnetic element — useful for coordinating with downstream breakers on a selective scheme.
Breaking capacity — what the numbers mean for your fault level
This breaker carries a rated ultimate short-circuit breaking capacity (Icu) of 440 kA at 240 V AC, 330 kA at 415 V and 440 V, 220 kA at 500 V, and 52.5 kA at 690 V. Those are very high numbers — this is a current-limiting MCCB intended for high-fault installations where the available fault current is substantial. At 690 V the 52.5 kA still covers most industrial distribution panels. The insulation voltage is rated 800 V, so it's suitable for 480/277 V and 600/347 V systems without issue.
Panel fit and integration
Dimensions are 105 mm wide, 181 mm high, 86 mm deep — a standard 3-pole MCCB footprint that drops into most SENTRON panelboards and switchgear. The front face carries IP40 protection, so it's fine in a clean indoor enclosure; no washdown rating. Rated power loss is only 1.2 W maximum, which keeps enclosure heating negligible. No undervoltage release, no communication function, no ground-fault monitoring on this variant — it's a straight line-protection breaker with the ETU340 trip unit.