The Siemens SENTRON 3VA1040-3ED32-0BC0 is a 3-pole molded case circuit breaker (MCCB) rated for 40 A at 40 °C, with a 75.6 kA interrupting capacity at 240 V. It's designed for line protection in distribution panels, and it ships with an undervoltage release and two HQ auxiliary switches integrated. The 70 mm depth and 76.2 mm width fit standard panel layouts — verify the 130 mm height clears your enclosure door clearance.
Interrupting capacity and thermal derating
The 75.6 kA at 240 V is the headline interrupting rating — that's the fault current it can safely clear at that voltage. At 415 V it drops to 52.5 kA, at 440 V to 32 kA, and at 500 V and 690 V it holds at 7.5 kA. The 40 A rating holds steady from 40 °C up to 50 °C; above that it derates to 38.4 A at 55 °C, 37.6 A at 60 °C, 36.8 A at 65 °C, and 36 A at 70 °C. If your panel ambient runs hot, size the load accordingly.
Auxiliary releases and wiring
The breaker includes an undervoltage release (UVR) as the auxiliary release type — that means it trips if control voltage drops below a threshold, useful for safety circuits or emergency-stop chains. The two HQ auxiliary switches provide status feedback for remote monitoring or PLC inputs. Rated insulation voltage is 800 V, and maximum power loss is 13.3 W — factor that into enclosure thermal calculations.