Siemens 3VA1163-6EF36-0JA0 — 63 A MCCB for high-fault panels
The breaker carries a 220 kA interrupting rating at 240 V, dropping to 154 kA at 415 V and 121 kA at 440 V, which puts it in the high-breaking-capacity class for main feeders or large secondary distribution where fault currents are severe.
The 63 A rating holds across ambient temperatures up to 50 °C (–); above that it derates linearly to 56.7 A at 70 °C. That thermal profile matters for enclosures with poor airflow — if the panel ambient runs at 55 °C, the breaker's usable current drops to 60.48 A, so the load must be sized accordingly. The 220 kA at 240 V is the SCCR (short-circuit current rating) the breaker can safely interrupt without welding contacts or venting arc gas — critical for coordination studies on 480 V / 277 V services where the available fault current can exceed 100 kA.
The 76.2 mm width is a standard 3-pole MCCB footprint — it occupies three 25.4 mm module positions on a DIN rail, so a panel designed for a typical 63 A frame will accept this without re-drilling the mounting plate.