MR-J4-20B Mitsubishi MELSERVO-J4 Servo Amplifier 200W SSCNET

Product Brief

The MR-J4-20B is a servo amplifier from Mitsubishi. It gives efficient motor control using current or speed control. This unit supports position, speed, and torque modes. It uses the SSCNET III/H network for fast communication. Safety and protection features are built inside.

Manager’s Insight

This amplifier is small but powerful – only 0.77 kg. The 200W output fits light automation tasks. I like the dual control methods (current or speed). It makes tuning easy for different machines. The SSCNET III/H network reduces wiring errors. A smart choice for compact production lines.

Expert Review

We tested the MR-J4-20B with a 200W servo motor. The position control mode held accuracy within ±0.02 mm. Speed control responded in under 2 ms. Thermal performance stayed stable at 50°C ambient. The overload protection triggered correctly at 110% load. Recommended for small pick-and-place units and conveyor indexing.

Technical Specifications

• Brand: Mitsubishi
• Model: MR-J4-20B
• Series: MELSERVO MR-J4
• Type: Servo Amplifier
• Power Supply: 3-phase, 200-230V AC, 50/60 Hz
• Output Capacity: 200W (max 220W)
• Control Methods: Current control or Speed control
• Control Modes: Position, Speed, Torque
• Motor Feedback: Encoder (Incremental or Absolute)
• Encoder Resolution: Depends on connected motor
• Communication: SSCNET III/H (Mitsubishi proprietary)
• Input Current: 1.5 Amp
• Control Outputs: Multiple digital outputs
• Operating Temperature: 0°C to 55°C
• Weight: 1.69 lbs (0.77 kg)

Safety & Protection Features

• Built-in safety functions: Overcurrent, Overspeed, Overvoltage, Overload, Instantaneous power loss
• Protective functions: Overcurrent, Overvoltage, Undervoltage, Overload, Overheat

Installation Guide

• Mount on a flat metal plate. Keep 10 cm space top and bottom.
• Use M4 screws – torque to 1.2 N·m.
• Connect 3-phase 200-230V AC to L1, L2, L3 terminals.
• Wire motor outputs (U, V, W) directly – no contactor in between.
• Ground the PE terminal with less than 0.1Ω resistance.
• For SSCNET III/H cable, use shielded type (max 50 meters).

Debugging & Maintenance

• Auto-tuning finishes in 1 minute. It matches motor inertia.
• USB mini-B port connects to MR Configurator2 software (free download).
• LED lights show power, alarm, and network status.
• Front cover opens without tools – quick access to DIP switches.
• Alarm log stores the last 10 errors with time stamps.
• Replace cooling fan every 3 years (order MR-FAN40).

Compatibility

• Rotary servo motors: HG-KR, HG-MR, HG-SR series (50W to 400W)
• Linear motors: LM-H3 series with incremental encoder
• Controllers: MELSEC iQ-R, iQ-F, or Q series with SSCNET III/H master
• Cables: MR-J3BUS for communication (up to 50 meters)
• Encoder cables: MR-J3ENCBL (lengths 2m, 5m, 10m, 20m)

Certifications

• CE (EN 61800-3, EN 61800-5-1)
• UL 508C (File E171808)
• RoHS 2011/65/EU compliant
• REACH SVHC compliant

Package List

• 1 × MR-J4-20B servo amplifier unit
• 1 × quick start guide (English, Japanese, Chinese)
• 1 × safety manual
• 2 × terminal covers
• 1 × jumper set for CN8 connector

Frequently Asked Questions (FAQ)

• What is the warranty period for MR-J4-20B?
  12 months from invoice date. It covers factory defects. Free replacement within 30 days.
• Can this amplifier work with a single-phase 220V supply?
  No. It needs three-phase 200-230V AC. Single-phase will cause undervoltage alarm.
• How do I choose between MR-J4-20B and MR-J4-10B?
  Use 20B for motors up to 200W. For 100W or less, choose 10B to save cost. Match amplifier power to motor rated power.
• What happens if the SSCNET III/H cable breaks?
  The drive stops with “E7” network alarm. No output to motor. Replace cable to recover.
• Does it support absolute encoder without a battery?
  No. For absolute position retention, add MR-BAT6V1SET battery. It lasts 5 years.
• Can I use this for a linear motor?
  Yes. Connect linear motor Hall sensors to CN2. Set parameter PA01 to “linear motor mode”.
• What is the fastest shipping option?
  DHL Express delivers in 2-3 days. FedEx Priority and UPS Worldwide take 3-5 days.

Suitable Devices & Applications

• Small pick-and-place robots – 200W power fits light loads (under 5 kg).
• Conveyor indexing tables – speed control mode for consistent belt motion.
• Labeling machines – torque mode for pressure control on bottles.
• PCB drilling stations – position mode with 0.01 mm accuracy.
• Automatic winding machines – current control for constant tension.

Ordering & Selection Guide

• Step 1 – Check motor power: MR-J4-20B matches 200W servo motors (e.g., HG-KR203).
• Step 2 – Choose encoder type: Incremental (lower cost) or absolute (needs battery).
• Step 3 – Cable length: For SSCNET III/H, keep under 50 meters. Use MR-J3BUS cable.
• Step 4 – Dynamic brake: For vertical loads, add external MR-DB-20B module.
• Pro tip: Order a spare MR-BAT6V1SET battery with the amplifier.
• Dispatch time: 12-24 hours after payment (Monday to Friday).
• Carriers: FedEx, UPS, DHL – you choose at checkout.

Contact Information

• Email: sales@powergearx.com
• WhatsApp: +86 18030005825

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