The Mitsubishi MR-J4-200B is a servo amplifier in the MR-J4 series, rated for 2000 W output capacity on a 200 V class supply. It accepts either single-phase or three-phase input, which gives flexibility when the panel has only one phase available — common on smaller machines or retrofit jobs where the three-phase run hasn't been pulled yet. The 2000 W rating means it's sized for a medium-load servo motor — think a 2 kW spindle or a feed axis on a machining center, not a tiny pick-and-place axis. The 200 V class input is standard for most Asian-origin machine tools; if your line is 400 V, you'll need a transformer or a different amplifier variant.
Power supply and interface
The main power bus runs on the 200 V class AC input, single or three phase. The control logic needs a separate 24 VDC ±10% supply at 0.3 A minimum, including the CN8 connector signal draw. That 24 V rail is typical for Mitsubishi servo interfaces — it powers the encoder, the brake release, and the STO (safe torque off) circuit if fitted. Don't share it with a noisy solenoid supply; a dedicated PSU keeps the encoder feedback clean. Power consumption is listed at 30 W for the control section itself, not counting the motor output. That's the heat the amplifier's internal logic and fan dissipate; the motor load is separate. No IP65 here; this lives inside a cabinet.