63 A MCCB with 121 kA interrupting capacity
Its interrupting capacity hits 121 kA at 240 V and 75.6 kA at 415 V — that's the fault current it can safely clear without welding contacts or rupturing the case. At 440 V it still holds 52.5 kA, and at 500 V or 690 V it's 11.9 kA. For a 63 A frame, those numbers give serious SCCR headroom in a 480Y/277 V or 400 V industrial panel. It's a straight line-protection breaker: mount it, land the conductors, and it clears overloads and short circuits without extra accessories.
At 55 °C it derates to 62 A, at 60 °C to 61 A, at 65 °C to 60 A, and at 70 °C to 58 A. That's a gentle slope — you lose only 5 A over a 30 °C rise — so it's comfortable in a warm enclosure as long as you don't crowd the top of the operating range. Dimensions: 130 mm tall, 101.6 mm wide, 70 mm deep. That 70 mm depth is shallow enough for most 200 mm deep enclosures; the 101.6 mm width (4 inches) is standard for a 4-pole MCCB footprint.