63 A MCCB with ETU550 — breaking capacity and thermal curve
The interrupting capacity reaches 187 kA at 240 V, 121 kA at 415 V and 440 V, 79 kA at 500 V, and 4.25 kA at 690 V — so the high short-circuit ratings at typical distribution voltages mean this breaker can sit close to the transformer without needing upstream current-limiting fuses. Thermal derating is minimal up to 50 °C (full 63 A), then drops to 60.6 A at 55 °C, 58.3 A at 60 °C, 55.9 A at 65 °C, and 53.6 A at 70 °C. That curve matters when the breaker lives in a crowded panel or near heat sources — the 70 °C rating is still 85% of the nominal, so you don't lose much headroom in a warm enclosure.
The breaker measures 105 mm wide, 181 mm tall, and 86 mm deep — standard 3-pole MCCB footprint for the SENTRON 3VA2 frame.
The ETU550 electronic trip unit supports communication and includes a voltage trigger. The basic switch element carries order code 3VA2163-5JP32-0AA0. Maximum power loss is 4 W. Mechanical endurance is 20,000 operations.