Mitsubishi MR-J4-70GF – EtherCAT Servo Amplifier for 0.75 kW MELSERVO-J4 Systems

The MR-J4-70GF is part of Mitsubishi Electric’s MELSERVO-J4 family, designed for fast, precise motion over EtherCAT in compact machinery. It pairs especially well with 0.75 kW HG-series servo motors (HG-KR/HG-SR), delivering crisp positioning, smooth speed control, and reliable torque response. From my experience, it’s a solid choice for packaging lines, indexing tables, pick-and-place feeders, and small machine tools where EtherCAT synchronization really matters.

Company’s Order Placement Process and Guarantees

• Warranty: 365 days
• Delivery: typically 1 week if in stock; no more than one month at the latest
• Payment: 50% advance payment; full payment prior to delivery
• Express options: FedEx, UPS, DHL

Key Features

• EtherCAT (CoE, CiA402) – Real-time control with standard EtherCAT profiles, easy to slot into multi-axis systems.
• 0.75 kW class – Sized for mid-range axes, often used on feeders, unwinders, and indexing mechanisms.
• High-resolution feedback – Works with Mitsubishi’s high‑resolution absolute/incremental encoders for tight positioning.
• Built-in STO safety – Dual-channel Safe Torque Off (typically PL d / SIL 2), helping you meet machine safety requirements with minimal wiring.
• Auto-tuning and vibration suppression – Speeds up commissioning and reduces mechanical resonance; you might notice quicker settling on light-load axes.
• Compact “book” form factor – Easy cabinet layout with vertical airflow; in many cases you can line up multiple amplifiers side-by-side.
• Service USB port – Parameter setup and diagnostics via PC software typically takes minutes, not hours.
• Regeneration handling – Built-in regenerative capability for this capacity; external resistor can be added if duty is heavy.

Technical Specifications

Related or Supporting Products

• MR-J4-70A – Same power class with pulse/analog command interface instead of EtherCAT.
• MR-J4-70B – SSCNET III/H network version for Mitsubishi motion systems.
• HG-KR73 / HG-SR73 – 0.75 kW servo motors compatible with MR-J4 amplifiers; high‑resolution absolute encoders.
• Absolute encoder battery (MR-BAT6V1SET) – Maintains multi‑turn absolute position when power is off.
• Shielded EtherCAT cables – CAT5e/CAT6 industrial, for reliable real-time comms and EMC compliance.
• External regenerative resistor (optional) – For high-inertia or frequent decel duty cycles when extra dissipation is needed.

Installation & Maintenance

• Cabinet environment – Mount vertically in a sealed control cabinet (IP54 or better in dusty areas). Provide top/bottom clearance for airflow; keep ambient 0–55°C.
• Power & wiring – Use appropriately rated breakers and fuses on the 200–240 VAC supply. Separate power and signal routes, and use shielded cables for feedback and network lines.
• Grounding & EMC – Single-point PE grounding. Bond panel doors and follow bonding straps for low impedance; it typically reduces nuisance noise on encoder lines.
• Network setup – Set EtherCAT node address and verify CoE parameters in the PLC/motion controller. A quick test jog via USB service software helps catch wiring mistakes early.
• Safety – Wire the dual STO channels through a certified safety relay or controller to meet PL d / SIL 2. Validate stopping performance during commissioning.
• Routine maintenance – Quarterly dust cleaning, fan/vent check, and terminal re‑torque. Yearly parameter backup and firmware check; battery replacement per motor encoder spec if using absolute mode.
• Tuning tips – Start with auto‑tuning, then apply vibration suppression. You might notice better throughput with modest gain increases after the machine warms up.

Quality & Certifications

• Conforms to CE marking
• UL/cUL listed (industrial control equipment)
• RoHS compliant
• Manufacturer warranty: typically 1 year; our supply warranty: 365 days

If you’re replacing an existing amplifier, send a quick photo of the rating label and the motor model—matching inertia and encoder type saves time. In many cases, MR-J4-70GF drops in with minimal cabinet changes, which is honestly why a lot of maintenance teams keep one on the shelf.