What the ratings mean for fit
The Siemens 3VA2140-7KQ42-0AA0 is a SENTRON molded case circuit breaker (MCCB) in the 3VA2 line-protection series, carrying 40 A continuous current flat across 40 °C to 70 °C — no derating needed up to that ceiling, which simplifies panel thermal budgeting. The 4-pole construction with ETU860 electronic trip unit provides adjustable long-time, short-time, instantaneous, and ground-fault protection via summation current sensing on L+N conductors. Interrupting capacity reaches 330 kA at 240 V, 242 kA at 415 V and 440 V, 187 kA at 500 V, and 3.7 kA at 690 V — figures that place this breaker squarely in high-fault-duty distribution, not branch-circuit-only applications. The IP40 front rating means the breaker face is protected against solid objects over 1 mm but not against moisture; it belongs in a dry enclosure, not a washdown environment.
Panel integration and mounting
The breaker occupies 140 mm width × 181 mm height × 86 mm depth — a 4-pole MCCB footprint that fits standard Siemens 3VA2 mounting bases and busbar systems. The 86 mm depth (3.39 in) is the dimension from the mounting plane to the farthest rear projection; verify gland-plate clearance and door swing before committing the panel layout. The IP40 front face accepts standard padlockable handle mechanisms and auxiliary contact add-ons.
Communication and monitoring capability
The ETU860 trip unit supports communication functions and other measurement functions, which means it can report trip data, load profiles, and event logs over a digital bus when paired with the appropriate communication module — a feature set that matters for predictive maintenance and remote troubleshooting on a production line. The ground-fault monitoring version uses summation current formation on the L+N conductor, so it detects residual currents without a separate core-balance transformer.