63 A MCCB with 121 kA interrupting capacity
The Siemens SENTRON 3VA1163-4EF46-0AA0 is a 4-pole molded case circuit breaker rated for 63 A continuous current (Iu) with a TM240 thermal-magnetic overcurrent release. 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. The TM240 release means the thermal element is fixed at 63 A (the frame rating), and the magnetic pickup is adjustable across a range — typical for protecting feeder cables or downstream distribution. No undervoltage release, no shunt trip, no communication module on this variant. It's a straight line-protection breaker: mount it, land the conductors, and it clears overloads and short circuits without extra accessories.
Thermal derating and panel fit
The 63 A rating holds flat from 40 °C to 50 °C ambient. 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. Maximum power loss is 17.3 W, which is modest for a 4-pole 63 A frame; plan ventilation if you're stacking several breakers in a sealed cabinet. 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. IP40 on the front means it's protected against tools and wires >1 mm, but not against dust ingress — keep it inside a panel, not on the machine surface.