What this MCCB carries and where it fits
The Siemens SENTRON 3VA1040-3ED36-0HC0 is a 3-pole molded case circuit breaker rated for 40 A continuous current at up to 50 °C ambient, with the thermal-magnetic TM210 release for line protection. It delivers 75.6 kA interrupting capacity at 240 V, 52.5 kA at 415 V, and 32 kA at 440 V — numbers that tell you it can handle high-fault downstream of a transformer or a large motor branch without upstream coordination headaches. The 70 mm depth and 76.2 mm width mean it fits standard SENTRON panel footprints; if you're swapping into an existing 3VA1010 cutout, the dimensions are identical, so no rewiring of the bus bars.
Thermal derating and what it means on a hot panel
At 40 °C, 45 °C, and 50 °C the breaker holds its full 40 A rating. Above that it starts to taper: 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 runs warm — say next to a drive cabinet or a transformer — you lose about 4 A at the high end. That's not a showstopper for most motor circuits, but if you're right at the limit on a continuous resistive load, factor it in. The operating range goes from -25 °C to 70 °C, so it handles a cold warehouse startup fine.
Auxiliaries and releases on this variant
This version ships with 2 auxiliary switches (HQ type) and a shunt trip release (STL) for remote tripping. The shunt trip is the integrated design with order code 3VA9688-0BL30 — it's a factory-fit accessory, not a field-add kit, so verify your BOM includes that if you need remote trip capability. There is no undervoltage release, no ground fault monitoring, no communication module, and no phase failure detection. It's a straight line-protection breaker with a voltage trigger for the shunt trip. The TM210 release is thermal-magnetic, fixed-trip, no electronic adjustment — set it and forget it.
Panel fit and IP rating
Front face carries IP40 protection — fine for a dry indoor panel, not for washdown or outdoor exposure. The 130 mm height, 76.2 mm width, and 70 mm depth match the 3VA1xxx family footprint, so it drops into existing SENTRON mounting plates and busbar systems without modification. The rated insulation voltage is 800 V, and the reference code per DIN EN 81346-2 is Q (switchgear).
Endurance and mechanical life
Latching endurance is rated at 15,000 cycles. That's the mechanical life before the latching mechanism is expected to wear out. For a line-protection breaker that sees maybe a few operations a year, that's effectively lifetime. For frequent switching applications — like a motor disconnect cycled daily — you'd want a contactor ahead of it.