The A9R74463 is a Schneider Electric Acti9 iID 4-pole residual current circuit breaker (RCCB) rated for 63 A continuous current with 300 mA earth-leakage sensitivity, Type AC, for 380...415 V AC 50/60 Hz networks. The 300 mA sensitivity means it's sized for general circuit protection against earth faults — not the 30 mA needed for personal shock protection in socket circuits, but the right threshold for distribution sub-mains or equipment where a lower trip would nuisance-trip on normal leakage.
Rated at 63 A (In) and 380-415 V AC, this RCCB handles the full current of a typical three-phase sub-distribution board or a large single-phase load block. The insulation voltage (Ui) is 500 V AC, and impulse withstand (Uimp) is 6 kV, so it's rated for standard 400 V-class panels with reasonable surge margins. That's the standard type for general-purpose circuits without electronic loads that generate pulsed or DC fault currents. If the downstream equipment includes VFDs, switched-mode supplies, or LED drivers, a Type A or Type B RCCB would be needed instead — this part is not suitable for those loads.
The 72 mm width (8 x 9 mm pitches) is standard for a 4P RCCB in the Acti9 range — it slots into a distribution board alongside MCBs and other modular devices. The toggle control and padlocking provision are standard for lockout/tagout procedures.