What this MCCB carries
The Siemens SENTRON 3VA1020-4ED36-0AE0 is a 3-pole molded case circuit breaker (MCCB) for line protection, rated at 20 A continuous current (Iu) with a TM210 thermal-magnetic release. Its interrupting capacity hits 121 kA at 240 V, 75.6 kA at 415 V, 52.5 kA at 440 V, and 11.9 kA at 690 V — so it handles high-fault scenarios on the secondary side of a distribution transformer without cascading upstream. The 20 A rating holds flat from 40 °C to 50 °C, then derates linearly to 18 A at 70 °C. That means if your panel ambient runs above 50 °C — say in a non-climate-controlled enclosure near a furnace line — you lose roughly 2 A of headroom. Plan the load accordingly. Four HQ auxiliary switches come built in (auxiliary contact version: 4 auxiliary switches HQ). No undervoltage release, no ground-fault module, no communication function — this is a straight thermal-magnetic breaker with aux contacts for status feedback. The TM210 release has a fixed time delay tr max of 1 s.
Panel fit and integration
Dimensions: 70 mm deep, 76.2 mm wide, 130 mm tall. That 76.2 mm width is a standard 3-pole MCCB footprint — it drops into a SENTRON panelboard or a DIN-rail adapter without surprises. IP40 on the front means it's splash-protected against tools and fingers but not washdown; keep it inside the enclosure.