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. Auxiliary switching is handled by 2 auxiliary switches plus 1 trip alarm switch, which can feed a PLC or alarm annunciator.
Panel fit and integration
Dimensions are 105 mm wide, 181 mm high, and 86 mm deep — a standard 3-pole MCCB footprint that drops into most Siemens SENTRON distribution panels and third-party enclosures with DIN-rail or screw-mount provisions. The 1.6 W maximum power loss is low enough that internal enclosure heating is negligible for most cabinet sizes.
Environmental tolerance
Operating temperature range is -25 °C to 70 °C, with storage from -40 °C to 80 °C. That covers unheated warehouses and outdoor-rated enclosures in most climates. No undervoltage release or ground-fault monitoring on this variant — those are separate add-on modules if your application requires them.