What this MCCB is and where it fits
The Siemens 3VA2040-7JQ32-0AA0 is a SENTRON molded case circuit breaker (MCCB) rated for 40 A continuous current on a 3-pole line-protection design. It carries a maximum interrupt capacity of 480 A, with breaking capacities of 330 kA at 240 V, 242 kA at 415 V and 440 V, 187 kA at 500 V, and 3 kA at 690 V — so the same breaker handles different fault-current levels across common industrial voltages without swapping frames. The 86 mm depth and 105 mm width fit standard DIN-rail panel layouts; the 181 mm height clears most enclosure gutters.
Thermal performance across the panel ambient range
The continuous current rating holds flat at 40 A from 40 °C through 70 °C ambient — no derating needed in a warm enclosure. That simplifies panel thermal budgeting: you don't have to oversize the breaker for a 50 °C switchroom or a cabinet sitting next to a drive.
Built-in communication and ground-fault monitoring
The breaker includes a communication function for integration into a monitored distribution system, plus ground-fault monitoring via summation current formation on the L-conductor. That saves an external ground-fault relay in panels where earth-leakage detection is required.