Siemens 3VA4120-4ED14-0AA0 — 1-Pole SENTRON MCCB, 20 A, 65 kA IC
It carries a TM210 thermal-magnetic trip unit, rated 20 A at 40 °C ambient, with a maximum interrupting capacity of 65 kA at 120 V AC. At 277 V the interrupting rating drops to 25 kA, and at 347 V to 14 kA — the standard derating curve for a 1-pole MCCB as system voltage increases. For a 415 V AC rated operating voltage, the interrupting capability is governed by the device manual's DC-network guidance.
Thermal-Magnetic Trip and Current Derating
The TM210 trip unit provides fixed thermal (overload) and magnetic (short-circuit) protection. The breaker is rated 20 A continuously at 40 °C and 45 °C, derating to 19 A at 50 °C and 55 °C, 18 A at 60 °C and 65 °C, and 17 A at 70 °C.
The breaker occupies a single 25.4 mm (1 in) pole width on the DIN rail, with a depth of 75.1 mm (2.96 in) and height of 129.4 mm (5.09 in). The 1-pole footprint matches standard SENTRON 3VA panel layouts; verify the busbar finger-reach depth if the enclosure has a shallow backpan. The storage minimum is the handling limit, not the running limit.