Integrator's note on the 3VA1020-3ED32-0AD0
The Siemens SENTRON 3VA1020-3ED32-0AD0 is a 3-pole molded case circuit breaker rated at 20 A continuous current (Iu) with a TM210 thermal-magnetic release. Interrupting capacity reaches 75.6 kA at 240 V, 52.5 kA at 415 V, and 32 kA at 440 V — figures that govern selectivity coordination downstream. The part carries three auxiliary switches (HQ) for status feedback; no undervoltage release, no ground-fault monitoring, no communication module. Mounts on a DIN rail or panel; front protection is IP40.
Thermal derating and what it means for panel loading
The breaker holds its full 20 A rating from 40 °C through 50 °C ambient. Above that, it derates linearly: 19.2 A at 55 °C, 18.8 A at 60 °C, 18.4 A at 65 °C, and 18 A at 70 °C. If the panel ambient runs hot — say, a sealed enclosure near a furnace line — size the load to the 70 °C figure, not the nameplate. The TM210 release is fixed thermal, not adjustable, so that derating curve is the only headroom you get.
Panel fit and dimensions
The breaker occupies 76.2 mm width, 130 mm height, and 70 mm depth — a standard 3-pole MCCB footprint for the SENTRON 3VA platform. Front IP40 keeps dust out of the enclosure; the three auxiliary switches (HQ) are wired for remote status. No trip indicator on this variant, so plan for an external indication circuit if the panel requires local fault annunciation.