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Precision Zone Expertly Repairs Drives-AC Servo Mitsubishi MR-S3

Here at Precision Zone, one of our specialties is the repair services of Mitsubishi servo units. One series that we often work on is the MR-S3 servo series.

Mitsubishi’s MR-S3 is a series of 3-axis integrated AC servo amplifiers. There are 4 different offerings of capacities ranging from 0.3kW up to 2.0kW. These units have a digital control that had replaced the analog circuitry of past series which now provides better response repeatability and reliability. This also leads to a reduction in parts and components which reduces the possibility of failure and increases reliability. These drives are designed for use with the reliable HA series servo motors, boasting quick response and a wide range of use.

When assessing the functionality of a drive, our repair team conducts a four-step check:

  • 1. Visual Overview
  • 2. Static Test
  • 3. Checks Under Power
  • 4. Alarm Codes Verification

This overview is Precision Zone’s basic troubleshooting process. Once our repair team starts on the job, we use specialized and customized testing fixtures, Huntron trackers, signal generators, oscilloscopes, milli and megaohm meters, as well as any other necessary tools we have available to assure quality repair work. Most importantly, every repair is fully tested in our custom-built simulators under load with a motor to replicate real-life working environment.

Precision Zone goes as far as using heating chambers and overnight dynamic testing, when applicable, to guarantee the performance of the repaired product when it arrives back with the customer.

Repair Process for Mitsubishi MR-S3 AC Servo Drives

Visual Overview

When conducting a visual check, the technician inspects the drive for any mechanical damage to the drive itself and any printed circuit boards (PCB). The technician then proceeds to verify connections are tight and correct inside the drive and there are no loose screws, wires or debris. Additionally, the unit is checked for any burn marks on the components, PCBs or chassis. During the visual inspection, excessive dirt on cooling components is noted as well as the functionality of the heat sink.

Basic Static Check

Input and Output Module Testing

Unfortunately, these servos do not have an easily accessible bus terminal to check the inputs and outputs. Here at Precision Zone we can use our Huntron to check the waveforms of the power rectification and inverting components to ensure that everything is functioning properly. We are able to statically check these components with the drive disassembled.

Common Alarms for the Mitsubishi MR-S3 Servo Drive Units

Alarm Code Description Quick Checks
10 Under Voltage
  • Verify incoming 3 phase power to the drive
  • Ensure all phases are present, balanced, and within the correct range
31 Over Speed
  • Check motor code to make sure the proper motor code/speed is selected
  • Reduce rapid traverse rate
  • Increase acceleration/deceleration time constant
  • Check cabling, especially between drive and encoder
  • Check position detector/encoder unit
32 Over Current
  • Check wiring
  • Meg out the motor cable and motor for issues with insulation resistance
  • Check for motor grounding or short circuits on the drive’s outputs
  • If alarm happens at power up, try to disconnect U, V, W cables (with power off) and power up. If alarm remains, check output transistors
37 Parameter Error
  • Check control for specific parameter that is being indicated
  • Verify all jumper and switch settings
  • Make sure any option boards are properly seated and making good connection
  • Check wiring and connections
50 Overload 1
  • Ensure that the motor has not overheated
  • Check wiring
  • Meg out the motor cable and motor for issues with insulation resistance
  • Check for motor grounding or short circuits on the drive’s outputs
  • If alarm happens at power up, try to disconnect U, V, W cables (with power off) and power up. If alarm remains, check output transistors

Alarms that begin with an ‘E’ indicate various warnings. These can be over regeneration warnings (E0), over load warnings (E1), and emergency stop warnings (E7) to name a few.

This list of checks for certain alarms is primarily a good starting point and if any further troubleshooting or technical support is needed feel free to contact us via phone or email to get in touch with our experienced tech support team.

Precision Zone offers free technical support on any component that you may be having issues with. We understand that when your machine goes down, your business stops. That is why our number one goal is to provide you with the best service possible so that you can get back up and running immediately. FFor any further product information or troubleshooting assistance is needed, please contact us via phone at 800-551-4420 or email us.

Precision Zone Repair Benefits for Mitsubishi MR-S3 Servo Drive Units

  • Free quotes and evaluations by our expert technicians include:
  • 12-Month Warranty on Our Parts and Labor
  • Decades of Industry Experience
  • Exchange Options
  • Rush Service Options

Contact Us To Start Your Repair Today!


Recently Repaired Products

Mitsubishi MR-S3-80BB-E01 image MR-S3-80BB-E01 is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Bad Capacitor(s), Bad Control Section/Board, Bad Magnetic Contactor, Relay, Bad Power Section/Board, Leaky Capacitors (Open, Corroded Traces)
Drive Type: MR-S AC Servo Drive
Axis Specification: 3 Axis
Denotes capacity of L axis: 1kW
Denotes capacity of M axis: 1 rank below L axis
Denotes capacity of S axis: 1 rank below L axis
Option card: no card

Mitsubishi MR-S3-80AA-E01 image MR-S3-80AA-E01 is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Bad Circuit Board Component(s), Bad Gate Section/Board, Bad Output Transistors/SCRs
Drive Type: MR-S AC Servo Drive
Axis Specification: 3 Axis
Denotes capacity of L axis: 1kW
Denotes capacity of M axis: same capacity as L axis
Denotes capacity of S axis: same capacity as L axis
Option card: no card

Mitsubishi MR-S3-33AA-Z33 image MR-S3-33AA-Z33 is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Bad Battery, Bad Capacitor(s), Bad Control Section/Board, Bad Cooling Fans, Bad Gate Section/Board, Bad Magnetic Contactor, Relay, Bad Power Section/Board, Excessive Dirt/Debris, Leaky Capacitors (Open, Corroded Traces)
Drive Type: MR-S AC Servo Drive
Axis Specification: 3 Axis
Denotes capacity of L axis: 300W
Denotes capacity of M axis: same capacity as L axis
Denotes capacity of S axis: same capacity as L axis
Option card: RF-333 for absolute value detection

Mitsubishi MR-S3-33AA-E01 image MR-S3-33AA-E01 is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Bad Capacitor(s), Bad Control Section/Board, Bad Gate Section/Board, Bad Magnetic Contactor, Relay, Bad Power Section/Board, Excessive Dirt/Debris, Leaky Capacitors (Open, Corroded Traces)
Drive Type: MR-S AC Servo Drive
Axis Specification: 3 Axis
Denotes capacity of L axis: 300W
Denotes capacity of M axis: same capacity as L axis
Denotes capacity of S axis: same capacity as L axis
Option card: no card

Mitsubishi MR-S3-80AA-E31 image MR-S3-80AA-E31 is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Bad Capacitor(s), Bad Circuit Board Component(s), Bad Gate Section/Board, Bad Magnetic Contactor, Relay, Leaky Capacitors (Open, Corroded Traces)
Drive Type: MR-S AC Servo Drive
Axis Specification: 3 Axis
Denotes capacity of L axis: 1kW
Denotes capacity of M axis: same capacity as L axis
Denotes capacity of S axis: same capacity as L axis
Option card: RF-313 for closed loop

Mitsubishi MR-S3-100BB-E01 image MR-S3-100BB-E01 is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Bad Gate Section/Board, Bad Magnetic Contactor, Relay, Bad Output Transistors/SCRs, Leaky Capacitors (Open, Corroded Traces)
Drive Type: MR-S AC Servo Drive
Axis Specification: 3 Axis
Denotes capacity of L axis: 2kW
Denotes capacity of M axis: 1 rank below L axis
Denotes capacity of S axis: 1 rank below L axis
Option card: no card

Mitsubishi MR-S3-100AA-E01 image MR-S3-100AA-E01 is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Bad Capacitor(s), Bad Control Section/Board, Bad Cooling Fans, Bad Gate Section/Board, Bad Magnetic Contactor, Relay, Bad Power Section/Board, Excessive Dirt/Debris, Leaky Capacitors (Open, Corroded Traces)
Drive Type: MR-S AC Servo Drive
Axis Specification: 3 Axis
Denotes capacity of L axis: 2kW
Denotes capacity of M axis: same capacity as L axis
Denotes capacity of S axis: same capacity as L axis
Option card: no card

Mitsubishi MR-S3-80AA-Z33 image MR-S3-80AA-Z33 is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Bad Capacitor(s), Bad Circuit Board Component(s), Bad Magnetic Contactor, Relay
Drive Type: MR-S AC Servo Drive
Axis Specification: 3 Axis
Denotes capacity of L axis: 1kW
Denotes capacity of M axis: same capacity as L axis
Denotes capacity of S axis: same capacity as L axis
Option card: RF-333 for absolute value detection

Mitsubishi MR-S3-40AB-E01 image MR-S3-40AB-E01 is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Bad Capacitor(s), Bad Gate Section/Board, Bad Magnetic Contactor, Relay
Drive Type: MR-S AC Servo Drive
Axis Specification: 3 Axis
Denotes capacity of L axis: 500W
Denotes capacity of M axis: same capacity as L axis
Denotes capacity of S axis: 1 rank below L axis
Option card: no card

Mitsubishi MR-S3-80BB-Z33 image MR-S3-80BB-Z33 is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Bad Capacitor(s), Bad Circuit Board Component(s), Leaky Capacitors (Open, Corroded Traces)
Drive Type: MR-S AC Servo Drive
Axis Specification: 3 Axis
Denotes capacity of L axis: 1kW
Denotes capacity of M axis: 1 rank below L axis
Denotes capacity of S axis: 1 rank below L axis
Option card: RF-333 for absolute value detection