The Siemens 3RV1041-4JA15 is a SIRIUS motor protection circuit breaker rated for 63 A continuous current with CLASS 10 trip characteristics, sized for a 30 kW motor at 400 V AC-3 duty. It combines short-circuit and overload protection in one device, eliminating the need for a separate overload relay on the line side of the contactor.
The 63 A continuous rating sets the upper bound for motor FLA you can protect — match it to the motor nameplate, not the supply transformer. Breaking capacity drops with voltage: 100 kA at 240 V AC, 50 kA at 400 V AC, 12 kA at 500 V AC, and 6 kA at 690 V AC. At 400 V, 50 kA covers most industrial service-entrance fault levels without needing current-limiting fuses upstream. The 6 kV surge voltage resistance (rated impulse withstand) means the insulation coordinates with standard distribution panels.
The 70 mm width, 165 mm height, and 174 mm depth are the envelope you need on the DIN rail — zero clearance required at the sides or rear, so you can butt it against adjacent devices.