The Schneider Electric A9N19806 is a C120H miniature circuit breaker from the Acti9 range, built for distribution duty in 50/60 Hz AC networks. Its 63 A rated current at 30 °C and D-curve magnetic trip (10 to 14 x In) mean it handles high inrush loads — motor starting, transformer energization, or welding equipment — without nuisance tripping on the magnetic element. Three poles protected, thermal-magnetic trip, and a clip-on mount for DIN rail. The tunnel terminals accept 1 to 50 mm² rigid or 1.5 to 35 mm² flexible, torqued to 3.5 N·m.
D-curve selectivity and coordination
The D-curve (10 to 14 x In magnetic trip) is the key differentiator versus a C-curve (5 to 10 x In) in the same C120H family. For a 63 A breaker, the D-curve magnetic pickup sits between 630 A and 882 A — deliberately high to ride through motor-start current without tripping. If your load is resistive or general-purpose with modest inrush, a C-curve sibling would trip faster on the magnetic element; the D-curve is the right call for inductive loads with a high locked-rotor ratio.
Panel integration
Clip-on DIN rail mount, 9 module pitches wide (9 x 17.5 mm = 157.5 mm), 86 mm tall, 73 mm deep. The 3-pole body fits standard distribution boards; the toggle actuator and ON/OFF indicator give local status at a glance. Earth-leakage protection requires a separate block — not integrated.