MR-J4-70B MELSERVO-J4 750W AC Servo Amplifier SSCNET III/H | Mitsubishi Electric

The Original New Mitsubishi Electric MR-J4-70B is a 750 W (0.75 kW) AC servo amplifier from the MELSERVO-J4 series, designed for high-precision motion control in industrial automation systems. It features a built-in dynamic brake and built-in regenerative resistor, operating on a 200–240 V AC single-phase or three-phase supply. The amplifier uses the SSCNET III/H high-speed optical fiber communication interface for synchronized multi-axis control with a communication speed of 150 Mbps full duplex, three times faster than conventional systems. The MR-J4-70B is compatible with Mitsubishi HG-KR and HG-SR series servo motors equipped with 22-bit absolute encoders, and supports advanced functions including vibration suppression control II, adaptive filter II, and one-touch tuning.

Core Engineering Highlights:
750 W (0.75 kW) rated output | 5.8 A rated current / 3.8 A input current | 200–240 V AC single-phase or three-phase input | SSCNET III/H optical fiber interface (150 Mbps full duplex) | Built-in dynamic brake + built-in regenerative resistor (20 W) | Safe Torque Off (STO) – SIL2 / PL e | 22-bit absolute encoder support | 0.222 ms / 0.444 ms / 0.888 ms communication cycle | IP20 protection | 0°C to +55°C operating temperature

Key Features:

• Original New Mitsubishi Electric MR-J4-70B servo amplifier

• 750 W (0.75 kW) rated output with 5.8 A rated current

• SSCNET III/H high-speed optical fiber communication for synchronized multi-axis control

• Built-in dynamic brake and built-in regenerative resistor (20 W) for reduced external components

• Safe Torque Off (STO) safety function compliant with IEC/EN 61800-5-2

• Supports 22-bit absolute encoder (serial communication)

• Speed frequency response of 2.5 kHz

• Advanced vibration suppression control II, adaptive filter II, and robust filter

• One-touch tuning for fast commissioning

• Fully closed-loop control with load-side encoder interface

• Machine diagnosis and power monitoring functions

• J3 compatibility mode for staged migration from MR-J2S/MR-J3 systems

• Forced ventilation cooling

• Compact dimensions: 60 × 168 × 185 mm

• Lightweight design: approx. 1.4 kg

Applications:

• Machine tool feed axes and precision positioning

• Packaging machinery servo axes

• Conveyor positioning and material handling systems

• Industrial robotics and automated assembly

• Semiconductor manufacturing equipment

• General high-precision motion control applications

Technical Specifications:

System Compatibility:

• Compatible with Mitsubishi Electric MELSERVO-J4 series architecture. Drive model and firmware compatibility should be verified before installation.

• Verified compatible servo motors include: HG-KR73, HG-KR43, HG-SR52, HG-SR72, HG-JR73, and equivalent HG series motors equipped with 22-bit multi-turn absolute encoder

• Also supports HG-KR73(B)W0C and HG-JR73(B)W0C functional safety motors when combined with MR-D30 functional safety unit

• For new installations requiring pulse train input, consider MR-J4-70A or MR-J4-70GF variants

• Commissioning via MR Configurator2 USB interface

Related Products:

• HG-KR73 – 750 W low-inertia servo motor, 22-bit absolute encoder, IP65

• HG-SR72 – 750 W medium-inertia servo motor, 22-bit absolute encoder

• MR-J4-70A – 750 W servo amplifier with pulse train interface

• MR-J4-70GF – 750 W servo amplifier with fully closed loop control

• MR-J4-70B-RJ020 – 750 W servo amplifier with J2S compatibility mode

• MR Configurator2 – PC software for parameter setting and tuning

PLC ERA is an independent industrial automation distributor supplying genuine Original New products through established global supply channels. All products are factory sealed when applicable and undergo quality inspection prior to shipment. Mitsubishi Electric and MELSERVO are trademarks of Mitsubishi Electric Corporation.