What it is and what it does
The Siemens SENTRON 3VA1040-3ED36-0HA0 is a 3-pole molded case circuit breaker (MCCB) rated for 40 A continuous current (Iu) at 40 °C, with a TM210 thermal-magnetic overcurrent release. It is a line-protection device — meaning it guards cables and distribution feeders against overload and short-circuit, not motor or generator protection. The breaker carries a shunt trip (STL) auxiliary release for remote tripping, but no undervoltage release, no auxiliary contacts, no ground-fault monitoring, and no communication module. The front face is IP40 rated, so it's fine inside a dry panel but not for washdown areas.
Breaking capacity — the real-world fault rating
This MCCB's interrupting capacity varies sharply with system voltage: 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 high enough for most low-voltage distribution boards on the secondary side of a 500 kVA transformer. At 690 V the rating drops to 7.5 kA — still adequate for many industrial loads but worth checking against the available fault current if you're feeding a 690 V drive panel. The 800 V rated insulation voltage (Ui) confirms the breaker's insulation system can handle 690 V line-to-line without derating the dielectric.
Thermal derating — the number that matters in a hot panel
The 40 A rating holds flat from 40 °C up to 50 °C — no derating needed in a typical 35 °C panel. At 55 °C it drops to 38.4 A, at 60 °C to 37.6 A, at 65 °C to 36.8 A, and at 70 °C to 36 A. If your panel ambient runs above 50 °C (common in a packed enclosure next to a furnace line), you need to account for that 4 A loss at the top end. The operating temperature range is -25 °C to +70 °C; storage range is -40 °C to +80 °C.
Physical fit and panel integration
Dimensions are 130 mm high, 76.2 mm wide, 70 mm deep. The 76.2 mm width is a standard 3-pole MCCB footprint — it fits the same panel cutout as most 3VA 3-pole breakers. The shunt trip accessory (order code 3VA9688-0BL30) is a separate add-on; it does not ship with the breaker. No auxiliary contacts are included, so if you need status feedback to a PLC, you'll need to order those separately. The breaker has no trip indicator, no phase-failure detection, and no communication function — it's a straightforward thermal-magnetic protector with remote trip capability via the shunt release.