What this MCCB does for a 40 A feeder
The Siemens SENTRON 3VA2040-6KQ32-0KA0 is a 3-pole molded case circuit breaker rated 40 A continuous at up to 70 °C ambient — no derating needed across the full temperature band from 40 °C to 70 °C, all at 40 A. That flat thermal curve simplifies panel design: one frame size covers the same load regardless of where it sits in the enclosure. Breaking capacity is the headline: 242 kA at 240 V, 187 kA at 415 V and 440 V, 121 kA at 500 V, and 3 kA at 690 V. The 3 kA at 690 V is a reminder this is a 600 V class frame — not for 690 V main feeders, but fine for 690 V motor circuits where the available fault current stays low. The adjustable thermal-magnetic trip range is 16 A to 64 A, with a factory-set full-scale of 40 A.
Panel fit and communication
A communication function is onboard, supporting integration with energy management or remote monitoring systems — useful for a panel that needs breaker status or load data on a bus. The supplied basic switch is 3VA20406KQ320AA0, confirming the internal mechanism.
Maximum power loss is 2.2 W — negligible for enclosure thermal calculations.
Ground-fault and auxiliary release details
The shunt trip (STL) allows a remote pushbutton, PLC output, or safety relay to open the breaker. No trip indicator is fitted, so remote indication depends on the communication function or auxiliary contacts.