63 A SENTRON MCCB with ETU320 — line protection, 187 kA interrupting capacity
The interrupting capacity reaches 187 kA at 240 V and holds at 121 kA through 440 V, then drops to 79 kA at 500 V and 3.4 kA at 690 V. That SCCR headroom at the lower voltages makes this breaker a strong candidate for high-fault utility or transformer-fed service entrances where coordination with upstream gear matters. For a panel that needs a reliable, no-frills line-side breaker with a proven trip curve, this is the right fit.
Thermal derating and mounting — panel integration notes
At 55 °C it derates to 60.6 A, at 60 °C to 58.3 A, at 65 °C to 55.9 A, and at 70 °C to 53.6 A.