What this MCCB is and what it protects
The Siemens 3VA2140-8HM46-0AA0 is a SENTRON molded case circuit breaker (MCCB) designed for line protection — meaning it sits upstream of a distribution bus or a feeder, not on a specific motor or load. Rated 40 A continuous with four poles, it handles three-phase plus neutral in a 400 V class panel. The 440 kA interrupting rating at 240 V drops to 330 kA at 415 V and 52.5 kA at 690 V — the breaker's arc chamber is sized for high-fault industrial mains, not just branch circuits.
Ground-fault monitoring and what it means in the panel
This variant carries summation-current ground-fault monitoring on L + N conductors. That means the breaker itself senses the vector sum of phase and neutral currents — if leakage to earth unbalances the sum, it trips. No external ground-fault relay or CT block needed; the monitoring is integral to the breaker housing. For a panel builder, that saves a DIN slot and a wiring step.
Dimensions and panel fit
The breaker measures 86 mm deep, 140 mm wide, and 181 mm high. That 140 mm width is the four-pole footprint — three-pole siblings in the same frame are narrower. Verify the existing panel cutout or mounting plate accommodates the 140 mm width before specifying the swap. The depth of 86 mm includes the arc chamber and terminal housing; leave clearance for cable bending radius below the line-side lugs.
Thermal performance across ambient temperature
Rated continuous current holds at 40 A from 40 °C through 70 °C ambient (–). No derating needed in a warm enclosure — the thermal-magnetic trip element is calibrated for that range. Power loss at rated load is 1.2 W maximum, negligible for enclosure heat budgeting.