The MR-J2S-200A is Mitsubishi Electric’s 2 kW MELSERVO-J2 Super series servo amplifier for 200 V single-phase or three-phase AC power supply with pulse train position command input — a legacy servo amplifier from Mitsubishi’s second-generation MELSERVO Super platform, providing 2 kW continuous servo control at 11 A for HC-SFS202 and HC-RFS203 series servo motors in active J2S-based servo systems where maintenance replacement is the primary requirement. In stock at Atlantech Drives. Request your quote within 24-48 hours with worldwide shipping and 12-month warranty.
What Is the MR-J2S-200A?
The MR-J2S-200A is a MELSERVO-J2 Super series servo amplifier providing 2 kW (2,000 W) continuous output power for Mitsubishi HC-SFS202, HC-RFS203, and equivalent 2 kW servo motors with the J2S-era serial encoder protocol. At 11 A continuous output current with 33 A peak (3×), the MR-J2S-200A addresses medium-load axis requirements in J2S-era servo systems — from CNC machining centre X/Y feed axes and robot shoulder axes to packaging line servo drives and material handling positioning systems built during the MELSERVO-J2 Super platform’s active production period (approximately 1999–2008). The amplifier accepts position command pulses via open-collector or differential pulse input at up to 500 kpps (differential), implementing the J2S three-loop servo control architecture with approximately 1.5 kHz current loop bandwidth and the J2S-generation auto-tuning algorithm. The RS-232C communication port connects to the legacy MR Configurator software for parameter access and servo tuning — MR Configurator2 compatibility for the MR-J2S-200A should be verified before assuming the current Mitsubishi commissioning tool provides full J2S parameter support. The MR-J2S-200A does not include a built-in STO safety function and is specified exclusively for direct maintenance replacement in existing J2S installations.
Key Technical Specifications
- Model: MR-J2S-200A
- Rated Output Power: 2 kW (2,000 W)
- Power Supply: 200–240 VAC single-phase or three-phase, 50/60 Hz
- Continuous Output Current: 11.0 A
- Maximum Output Current: 33.0 A (3× continuous peak)
- Compatible Servo Motors: HC-SFS202, HC-RFS203 (J2S/J3-era motors)
- Command Interface: Pulse train input (open-collector or differential)
- Maximum Input Pulse Frequency: 500 kpps (differential), 200 kpps (open-collector)
- Encoder Interface: Serial encoder (J2S-era HC motor encoder protocol)
- Safety Function: None built-in
- Regenerative Brake: Built-in, external regenerative resistor connectable
- Communication: RS-232C (MR Configurator legacy software)
- Operating Temperature: 0°C to 55°C
- Dimensions (W × H × D): 70 mm × 160 mm × 155 mm
- Weight: Approx. 1.8 kg
Series Comparison & Selection Guide
Within the MR-J2S-A pulse train sub-series, the MR-J2S-200A is the mid-range model between the 1 kW MR-J2S-100A and the 3.5 kW MR-J2S-350A. The 2 kW power class was historically the most commonly specified J2S amplifier for machine tool feed axes — at 200 VAC and 11 A continuous, the 2 kW motor provides adequate thrust for 500–800 mm travel ball screw axes in vertical and horizontal machining centres at the rapid traverse speeds typical of J2S-era CNC equipment. When comparing J2S to later generations, the MR-J2S-200A provides 2 kHz less current loop bandwidth than the MR-J3-200A (1.5 kHz versus 2 kHz), 2× lower encoder resolution (J2S encoder base resolution versus J3’s 17-bit), and approximately half the auto-tuning capability accuracy for high-inertia systems. These performance differences are rarely the primary driver for maintenance replacement decisions — the more critical factors are the increasing difficulty of sourcing authentic MR-J2S-200A units, the risk of DC bus capacitor failure in units approaching 15+ years of service, and the incompatibility with any currently manufactured Mitsubishi servo motor that makes motor failure a system-level crisis rather than a component replacement. The MR-J2S-200A → MR-J4-200A + HC-SFS202 → HG-SR202 upgrade path provides current-platform capability at the cost of simultaneous motor and amplifier replacement, complete re-cabling (encoder cable and motor power cable), and servo re-tuning — a planned shutdown task rather than an emergency repair.
Expert Tips
For MR-J2S-200A amplifiers approaching 12–15 years of service, the most productive preventive maintenance action is to read and archive the complete parameter set using the legacy MR Configurator software before a failure occurs — this parameter backup enables rapid restoration of servo performance after an emergency replacement without relying on machine documentation that may be incomplete or outdated. Connect MR Configurator to the MR-J2S-200A via the RS-232C port, use the parameter read function to download all servo parameters to a file, and store the file with the machine documentation and a spare copy off-site. When sourcing replacement MR-J2S-200A units from the aftermarket, request that the supplier provide the firmware version of the specific unit before shipping — J2S firmware versions affect specific parameter availability and auto-tuning behaviour, and a replacement unit with significantly different firmware than the original may exhibit different servo response with the same parameter settings, requiring re-tuning. For machines where the MR-J2S-200A’s cooling fan has been replaced previously, verify that the replacement fan has the correct voltage and airflow specification for the MR-J2S-200A housing — incorrect fan specifications (lower airflow, wrong voltage) installed by non-specialist maintenance can cause the amplifier to overheat at ambient temperatures that the original fan would have handled comfortably, leading to premature AL.46 overtemperature alarms. For J2S-era machines in high-ambient-temperature installations (above 40°C), reduce the servo axis duty cycle during peak ambient temperature periods if AL.46 overtemperature alarms become more frequent — this symptom indicates the cooling capacity is marginal for the current operating conditions and predicts a more severe thermal event if not addressed.
Frequently Asked Questions
Q: Can the MR-J2S-200A’s parameters be transferred directly to an MR-J3-200A replacement amplifier?
A: No direct parameter transfer is possible between MR-J2S and MR-J3 generations. The parameter numbering schemes, parameter names, and available parameter functions differ significantly between J2S and J3. MR Configurator2 does not include a J2S-to-J3 parameter conversion function equivalent to the J3-to-J4 conversion. When upgrading from MR-J2S-200A to MR-J3-200A or MR-J4-200A, servo re-tuning from factory defaults (using auto-tuning as a starting point) is the correct approach, using the archived J2S parameter values as reference for the mechanical system characteristics and previous servo response settings.
Q: Is it possible to operate an MR-J2S-200A with the external regenerative resistor from an MR-J3-200A?
A: The external regenerative resistor connection terminals on the MR-J2S-200A use the same P and C terminal designation as MR-J3 and MR-J4 amplifiers, and the resistor function (dissipating regenerative braking energy in an external resistor) is identical across generations. Provided the resistor’s resistance value and wattage rating are within the MR-J2S-200A hardware manual’s specified external resistor parameters, an MR-J3-series external regenerative resistor (MR-RB series) can be connected to the MR-J2S-200A’s P and C terminals. Verify the resistance value compatibility — the MR-J2S-200A may have a different minimum external resistor resistance specification than the MR-J3-200A.
Q: What is the typical lead time for sourcing an MR-J2S-200A replacement from the aftermarket in 2024–2025?
A: Lead times for MR-J2S-200A units from the aftermarket vary significantly — specialist industrial electronics distributors including Atlantech Drives maintain verified stock for immediate dispatch, while generalist online marketplaces may list units with extended lead times or uncertain authenticity. For machines where MR-J2S-200A failure would cause critical production downtime, maintaining one spare unit in the machine’s spare parts inventory is strongly recommended given the unpredictable availability of this discontinued model.
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