2 kW, 30 A — what the ratings mean for your axis
The MR-J4-200B-RJ is a Mitsubishi Electric servo amplifier from the MR-J4 Series, delivering 2 kW rated output and drawing 30 A at 240 VAC input. That 30 A figure is the line-side current the drive pulls under full rated load — it sizes the upstream branch circuit, the magnetic contactor, and the power-factor correcting reactor. The recommended contactor is a DUD-N30, and the power-factor reactor is a 30 A frame rated for 20 A continuous, whether the reactor is used or not. The RJ suffix means this unit is compatible with the Mitsubishi conversion unit, which adapts the servo amplifier for use with a different motor feedback or power interface. If your BOM calls out the RJ variant, the standard MR-J4-200B won't drop in without the conversion adapter.
Environmental limits and mounting
Rated for indoor use up to 2000 m altitude, free of corrosive gas, flammable gas, oil mist, and excessive dust. Vibration resistance is 5.9 m/s² across 10–55 Hz in all three axes — suitable for panel mounting on a machine frame or cabinet wall without additional isolation for typical industrial vibration.