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 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.
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 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.