Its headline interrupting rating is 220 kA at 240 V, dropping to 154 kA at 415 V and 121 kA at 440 V — figures that place it in the high-capacity tier of the 3VA line, sized for fault currents at the main distribution board rather than a downstream subfeed. The TM240 release is a fixed thermal-magnetic unit — no interchangeable trip block, no electronic adjustment. That means the 20 A rating is the hard ceiling; if the load draws more, step up to the next frame size. The breaker carries three HQ auxiliary switches, which gives the panel builder a spare N.O./N.C. pair beyond the standard alarm contact for remote status or PLC feedback. Keep it inside a cabinet unless you add a cover.
Above that it begins to taper: 19.2 A at 55 °C, 18.8 A at 60 °C, 18.4 A at 65 °C, and 18 A at 70 °C (–).
Selectivity and coordination notes
For DC applications, Siemens directs the installer to the 3VA device manual — the standard AC interrupting ratings do not apply in DC circuits.