What this MCCB is and what it does
The Siemens 3VA1140-4ED22-0AA0 is a SENTRON molded case circuit breaker (MCCB) designed for line protection in distribution panels. It's a 2-pole unit rated 40 A at 40 °C, with a TM210 thermal-magnetic overcurrent release — the thermal element handles overloads, the magnetic element handles short-circuits. The breaker carries a 121 kA breaking capacity at 240 V AC and 75.6 kA at 415 V AC, so it can safely interrupt high fault currents without upstream coordination issues in most commercial and light industrial panels.
Ratings and what they mean for fit
The 40 A rating holds across 40 °C to 50 °C ambient (no derating needed up to 50 °C), then drops to 39 A at 55 °C and 37 A at 70 °C. That thermal curve matters if the breaker sits in a warm enclosure — you don't lose headroom until the ambient passes 50 °C. The 121 kA at 240 V AC is the interrupting rating; at 415 V AC it's still 75.6 kA, which covers most transformer-fed secondary faults. Rated insulation voltage is 500 V, operating voltage 415 V AC or 250 V DC. The front panel carries IP40 protection — fine for a dry indoor panel, not for washdown areas.
Panel integration
The breaker measures 70 mm deep, 50.8 mm wide, and 130 mm high — a 2-pole footprint that fits standard DIN-rail or panel-mount enclosures. No communication function, no undervoltage release, no ground-fault monitoring on this variant. The TM210 release is fixed, so coordination studies should account for its thermal-magnetic curve. Power loss is 7.2 W maximum at rated load — negligible for thermal budgeting in a typical distribution panel.