The Siemens 3VA2140-5HM42-0AA0 is a SENTRON 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 that ceiling. Four poles, line protection design, with ground-fault monitoring via summation of L + N conductors. Breaking capacity hits 187 kA at 240 V, 121 kA at 415 V, and still holds 75.6 kA at 500 V; at 690 V it drops to 3.7 kA, so verify the available fault current at your service voltage before committing the BOM line.
What the ratings mean for fit
The 40 A continuous rating is flat from 40 °C to 70 °C — that's the full operating range of the breaker. No thermal derating curve to calculate; the part is designed to carry its nameplate current at any ambient within that span. The 800 V rated insulation voltage means it's suitable for 480 V and 600 V class systems with margin. The 4-pole construction allows it to switch a neutral conductor alongside the three phases, which is required for some ground-fault schemes and for certain IEC distribution panels.
Panel integration and mounting
Dimensions: 86 mm deep, 140 mm wide, 181 mm tall. The 140 mm width on a 4-pole MCCB is standard for the SENTRON 3VA2 family — it occupies the same footprint as other 4-pole breakers in the series. No communication function, no undervoltage release, no voltage trip — this is a straight thermal-magnetic line protection breaker with ground-fault monitoring. The ground-fault monitoring uses summation current formation on L + N, which means it detects residual current by comparing the vector sum of phase and neutral currents; no external CT required.