What this 40 A MCCB delivers — and what the ratings actually mean for your panel
The Siemens SENTRON 3VA2140-5HN42-0AA0 is a 4-pole molded case circuit breaker (MCCB) rated for 40 A continuous current across the full ambient range from 40 °C to 70 °C — no derating needed up to that ceiling, which simplifies panel build in warm enclosures or near heat sources. Breaking capacity hits 187 kA at 240 V AC and 121 kA at 415/440 V, tapering to 75.6 kA at 500 V and 3.7 kA at 690 V — the 690 V figure is low enough that you need to verify coordination upstream if the service voltage sits near that ceiling.
Dimensions are 181 mm height, 140 mm width, 86 mm depth — standard SENTRON 3VA footprint for a 4-pole frame at this rating. Power loss is rated at 1.6 W maximum — negligible for thermal budgeting inside a crowded panel.