What the interrupting ratings mean for your panel
The Siemens 3VA1140-6EE46-0AA0 is a SENTRON molded case circuit breaker (MCCB) in the 3VA1 line-protection family, rated 40 A continuous with a TM220 thermal-magnetic release. The 4-pole frame handles three-phase plus neutral, and the interrupting ratings tell you where it can sit in a distribution board: 220 kA at 240 V AC, 154 kA at 415 V, 121 kA at 440 V, and 17 kA at both 500 V and 690 V. That 220 kA figure at 240 V means it can clear a bolted fault on a large step-down transformer secondary without the arc re-striking — the kind of fault current you see on a 750 kVA unit. At 415 V the 154 kA still covers most industrial main switchboards; the drop to 17 kA above 500 V is the limit of the TM220 release's magnetic blowout design, so for 690 V applications verify the available fault current is under that ceiling.
Thermal derating and continuous current
The 40 A rated continuous current (Iu) holds flat from 40 °C to 50 °C — no derating needed in a typical 40 °C panel. At 55 °C it drops to 39 A, at 65 °C to 38 A, and at 70 °C to 37 A. If the breaker sits next to high-wattage contactors or drives in a sealed enclosure, factor that 37 A floor at 70 °C into your bus sizing.
Mechanical endurance and power loss
Rated for 20,000 mechanical operations — that's a solid number for a line-protection MCCB that sees occasional switching, not daily motor starts. Maximum power loss is 10.8 W, which is modest for a 4-pole 40 A frame; it won't drive much additional cooling in a ventilated panel.
Panel fit and environment
Dimensions are 101.6 mm wide, 130 mm high, 70 mm deep — a 4-pole MCCB that fits a standard 100 mm-wide DIN-rail or panel-mount footprint. Front protection is IP40, so it's fine for a clean indoor panel but not for washdown areas. Storage range is -40 °C to 80 °C; operating range is -40 °C to 70 °C. The TM220 release is a fixed thermal-magnetic type — no electronic trip unit, no communication module, no ground-fault monitoring. It's a straightforward line-protection breaker: set it, wire it, forget it.