What this MCCB is and where it lands
The Siemens 3VA1120-4ED26-0AA0 is a SENTRON molded case circuit breaker (MCCB) designed for line protection in distribution panels. It's a 2-pole unit with a TM210 thermal-magnetic overcurrent release, meaning it handles both overload and short-circuit protection in one package. Rated current holds at 20 A across the 40 °C to 55 °C band, then derates to 19 A at 60 °C through 70 °C — useful to know if the breaker sits near other heat sources in a crowded enclosure. Breaking capacity is 121 kA at 240 V AC and 75.6 kA at 415 V AC — that's high-interrupt capability for a 2-pole frame, sized for industrial service-entrance or sub-distribution where fault currents are substantial. The insulation voltage is rated 500 V, and operating voltage goes to 415 V AC or 250 V DC. Front IP40 protection means it's splash-resistant from the front face but not sealed for washdown; mount it inside a panel, not exposed to hose spray.
Panel fit and wiring
Dimensions are 70 mm deep, 50.8 mm wide, 130 mm tall — the 50.8 mm width is a standard 2-inch footprint that matches most 2-pole MCCB mounting bases. No undervoltage release or shunt trip on this variant, and no communication module; it's a straight thermal-magnetic breaker with no auxiliary signaling. Power loss is 8 W maximum at rated load — factor that into enclosure thermal calculations if grouping several breakers.