Mitsubishi Electric MR-J3-350A AC Servo Amplifier
A discontinued 200 V-class MELSERVO-J3 amplifier for 3.5 kW servo applications using the general-purpose command interface.
Key Information
MR-J3-350A is a Mitsubishi Electric MELSERVO-J3-A servo amplifier in the 3.5 kW capacity class. It provides a general-purpose command interface and dedicated motor, encoder, I/O, monitor and communication connections.
The amplifier is discontinued. Replacement planning must identify the connected servo motor, command method, feedback arrangement, regenerative hardware, parameter set and machine safety circuit rather than matching capacity alone.
Functions
- Controls a compatible Mitsubishi servo motor through pulse-train or analog-command functions supported by the J3-A platform.
- Provides a five-digit status and alarm display with local MODE, UP, DOWN and SET keys.
- Supports parameter, diagnostic and commissioning access through USB and RS-422 communication connectors.
- Maintains absolute-position data when the specified battery and compatible encoder arrangement are used.
Specifications
| Manufacturer | Mitsubishi Electric |
|---|---|
| Model | MR-J3-350A |
| Series | MELSERVO-J3-A |
| Applicable Servo Capacity | 3.5 kW class |
| Rated Output Voltage | 3-phase 170 V AC |
| Rated Output Current | 17.0 A |
| Main Circuit Supply | 3-phase 200–230 V AC, 50/60 Hz |
| Command Platform | General-purpose interface |
| Display | Five-digit, seven-segment LED |
| PC Communication | USB and RS-422 |
| Main Power Connector | CNP1 |
| Control / Regenerative Connector | CNP2 |
| Motor Power Connector | CNP3 |
| Encoder Connector | CN2 |
| I/O Connector | CN1 |
| Analog Monitor Connector | CN6 |
| Lifecycle | Discontinued |
Installation
- Verify the exact servo motor, encoder cable, motor cable, command wiring and regenerative option before replacement.
- Follow the specified vertical mounting, ventilation and grounding arrangement; close mounting requires the J3 derating conditions to be observed.
- Isolate all supplies and wait for the charge lamp to go out before touching wiring or reconnecting cables.
- Transfer parameters deliberately, then prove direction, limits, emergency stop, brake control and machine interlocks at restricted motion.
Lifecycle
- Archive the installed parameter file, alarms, wiring diagrams and amplifier nameplate before removal.
- Treat a newer MELSERVO generation as a migration project because motor, feedback, cabling, command interface and tuning can change.
- Keep the removed amplifier in dry ESD-safe packaging with connectors protected.
FAQ
Can MR-J3-350A be replaced only by matching the 3.5 kW rating?
No. Motor model, encoder type, command interface, supply, regenerative arrangement, safety wiring and parameter functions must also be matched.
What records are needed before quoting MR-J3-350A?
Provide the amplifier and motor nameplates, parameter backup, command-source details, connector photographs and the installed regenerative option.
Does an MR-J3-350A migration retain the existing motor and cables automatically?
No. Retention depends on the chosen successor platform and must be confirmed for the exact motor, feedback, connectors and cable lengths.
What should be checked before energizing a replacement MR-J3-350A?
Check protective earth, power phase, motor wiring, encoder connection, emergency stop, limits, brake sequence and the restored parameter set.
Why is the charge lamp important when servicing MR-J3-350A?
It indicates stored main-circuit voltage; approved isolation and discharge verification remain necessary before connections are touched.
Which commissioning tests reduce risk after an MR-J3-350A exchange?
Use controlled power-up, alarm review, inhibited-motion checks, low-speed direction testing, tuning review and the machine maker’s safety validation.
