What this MCCB does for a motor circuit
The Siemens SENTRON 3VA2140-5MN32-0AJ0 is a 3-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 the 70 °C ceiling. Its interrupting capacity sits at 187 kA at 240 V, 121 kA at 415 V and 440 V, 75.6 kA at 500 V, and 3.7 kA at 690 V, which covers most low-voltage distribution and motor branch circuits you'll encounter in an industrial panel.
Motor protection and phase loss coverage
This breaker is explicitly designed for motor protection, with built-in phase failure detection — meaning it will trip on a lost phase before the motor overheats from single-phasing. The trip indicator confirms the breaker opened on a fault, not a manual disconnect.
The 1.6 W maximum power loss is low enough that internal enclosure heating is negligible for most cabinet sizes.
Environmental tolerance
That covers unheated warehouses and outdoor-rated enclosures in most climates.