What the ratings mean for fit
The Siemens 3VA1040-3ED36-0KC0 is a SENTRON molded case circuit breaker (MCCB) for line protection — three poles, rated continuous current Iu of 40 A, with a TM210 thermal-magnetic overcurrent release. The interrupting ratings tell you where it can safely clear a fault: 75.6 kA at 240 V, 52.5 kA at 415 V, 32 kA at 440 V, and 7.5 kA at 690 V. That 75.6 kA at 240 V is the headline figure — it means this breaker can interrupt a fault current up to that level without welding its contacts or venting plasma into the enclosure, which is the key number for a panel builder sizing the SCCR on a 240 V distribution board.
Thermal derating and ambient temperature
The 40 A rating holds up to 50 °C ambient. Above that, the TM210 release begins to derate: 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 the panel ambient runs hot — say, near a bank of drives or inside a sealed enclosure in a foundry — plan for that curve. The breaker itself operates from -25 °C to 70 °C and stores from -40 °C to 80 °C, so the thermal limit is the release, not the housing.
Auxiliaries and integration
This variant ships with two auxiliary switches (HQ type) and a shunt trip (STL) for remote tripping. The auxiliary release is listed as order code 3VA9688-0BL33. No undervoltage release, no ground-fault monitoring, no communication module, no phase-failure detection — this is a basic line-protection MCCB with a voltage-trigger capability via the shunt trip. Front IP40 keeps dust out of the enclosure; the breaker is sized for a standard 3-pole DIN-rail or panel-mount footprint. Dimensions: 130 mm high, 76.2 mm wide, 70 mm deep.