What this MCCB is and what its ratings mean for your panel
The Siemens SENTRON 3VA2040-8JP42-0AA0 is a 4-pole molded case circuit breaker (MCCB) rated for a continuous current of 40 A across the full ambient range from 40 °C to 70 °C — no derating needed up to that ceiling. That means you can size the breaker for a 40 A load and not worry about temperature rise in a warm cabinet, as long as you stay below the 70 °C operating limit. The ETU550 electronic trip unit gives you adjustable overload and short-circuit protection curves, which is what you want for coordinating with downstream breakers or protecting a specific load like a motor or a feeder. The breaking capacity is the headline number here: 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. That is a very high interrupting rating — it means this breaker can safely clear a fault on a high-capacity transformer or a large bus without needing an upstream current-limiting fuse. For a 40 A frame, that kind of SCCR headroom is unusual; it tells me this is built for high-fault installations where you need selectivity and don't want to cascade a trip upstream. 4-pole design switches all three phases plus neutral.
Communication and integration into a control network
This MCCB includes a communication function for integration with automation systems via a communication module.
Dimensions and panel fit — what the 86 mm depth means for your enclosure
The physical footprint is 140 mm wide by 181 mm high by 86 mm deep. The 86 mm depth is the dimension from the mounting surface to the back of the breaker — important when you are fitting it into a shallow enclosure or a panel with limited clearance behind the gland plate. The 140 mm width for a 4-pole MCCB is standard for the frame size; it will fit the usual DIN-rail or panel-mount cutout for this class of breaker.