What it is and what it does
The Siemens 3VA2140-5HL42-0AA0 is a SENTRON molded case circuit breaker (MCCB) rated for 40 A continuous current with a 4-pole configuration and an ETU320 electronic trip unit. It's built for line protection in distribution panels — think feeder circuits, main switchboards, or sub-distribution where you need adjustable overload and short-circuit protection without a separate relay. The ETU320 release gives you adjustable N-conductor protection (OFF or 100%) and a fixed thermal-magnetic curve for the 40 A frame. No undervoltage release, no communication module, no voltage trigger — it's a straight MCCB for hardwired protection, not a smart breaker. The interrupting ratings climb to 187 kA at 240 V AC and stay at 121 kA at 415 V and 440 V AC, then drop to 75.6 kA at 500 V and 3.7 kA at 690 V — so at typical 400 V distribution it handles serious fault current without cascading upstream.
Current rating holds across the temperature range
Unlike many MCCBs that derate above 40 °C, this one holds its 40 A rating from 40 °C all the way up to 70 °C. That means no re-rating if the panel runs hot — useful in a crowded enclosure or a warm plant environment. The rated insulation voltage is 800 V, and the operating voltage maxes at 690 V AC, so it's comfortable on 400 V and 480 V systems with headroom.
Physical fit and panel integration
The breaker measures 86 mm deep, 140 mm wide, and 181 mm tall — a 4-pole MCCB that fits a standard distribution panel footprint. Front protection is IP40, so it's fine in a closed cabinet but not for washdown areas. No trip indicator on the front, so you'll rely on the panel's own indication or the handle position to spot a tripped state.