What this servo amplifier is and what it does
The Mitsubishi MR-J4-200A4-RJ is a servo amplifier from the MR-J4 series, rated for 2 kW continuous output on a 3-phase 400 VAC supply. It runs full closed-loop control, meaning the drive continuously compares the encoder feedback against the commanded position and corrects in real time — no position drift under load. This is the kind of loop you spec for a tool changer or a feed axis where the motor has to hold position against cutting forces or a heavy carriage. The interface is marked general-purpose, so it accepts standard step/direction or analog torque/speed commands from a PLC or motion controller — no proprietary fieldbus card required for basic positioning. At 2 kW output and 400 VAC three-phase input, it drives a servo motor in that power band without a step-down transformer.
Where you'd see this in a plant
In a mineral processing or mining environment, this amplifier would live inside a climate-controlled MCC or drive cabinet, not out on the grizzly. The 2 kW rating suits a moderate-load axis — a conveyor transfer gate, a flotation cell reagent pump, or a crusher feed roll. Full closed-loop control means the drive compensates for belt stretch or gearbox backlash; if the encoder sees the load lagging, it adds torque to close the gap. That matters when a jammed rock on a feed belt would otherwise push the position error past the trip limit.