63 A MCCB with 242 kA interrupting capacity — what the ratings mean for your panel
The Siemens SENTRON 3VA2063-6HL32-0AH0 is a 3-pole molded case circuit breaker rated for 63 A continuous current (Iu) across ambient temperatures from 40 °C to 50 °C without derating — at 55 °C it still holds 60.6 A, and at 70 °C it derates to 53.6 A, so you can mount it in a warm enclosure without oversizing the frame. Its headline breaking capacity hits 242 kA at 240 VAC and 187 kA at 415 VAC, which places it in the high-interrupting category — useful for large transformer secondaries or bus-tie applications where fault current runs high. The ETU320 electronic trip unit handles the overcurrent protection curve, and the breaker ships with 2 auxiliary switches plus 1 trip alarm switch (HQ type) for remote status feedback. Rated insulation voltage is 800 V, so it can sit on 690 V systems (where its breaking capacity is still 4 kA) without derating the insulation path.
Panel integration — dimensions and protection
The breaker measures 105 mm wide, 181 mm tall, and 86 mm deep — a standard MCCB footprint that fits most DIN-rail or screw-mounted panel layouts without surprises. Front-side protection is IP40, meaning it's sealed against tools and wires over 1 mm but not against moisture — keep it inside a dry enclosure, not in a washdown zone. Maximum power loss is 5.4 W, which is low enough that ventilation slots in a typical IP54 cabinet handle the heat without forced cooling.
What it does — and does not — include
This is a line-protection version (not motor-protection), so the trip unit is set for cable and busbar protection curves. It has no undervoltage release, no shunt trip, no ground-fault monitoring, and no communication module — it's a straight thermal-magnetic replacement with electronic trip adjustment. The trip indicator is present, so after a fault you get a visual flag that the breaker opened on overcurrent rather than being manually switched off. Storage temperature range is -40 °C to 80 °C, and operating range is -25 °C to 70 °C — fine for unheated warehouses or outdoor cabinets in temperate climates.