Our Team Expertly Repairs Mitsubishi MR-S11/MR-S12 AC Servo Drives

Here at Precision Zone, one of our specialties is the repair services of Mitsubishi AC Servo drives. One series that we often work on is the MR-S11/MR-S12 AC Servo series.

Mitsubishi MR-S11/MR-S12 AC servo drives are a direct replacement for the earlier MR-S1/MR-S2 units, respectively. These are offered in a wide variety of sizes starting at 200W and going up to 9000W. There are option cards available for these that are used when a closed-loop system is in place or absolute value detection is required.

A few of the features that this series offers are an enhanced all-digital control which was used previously in the conventional MR-S series systems, individual CPUs being used to control individual axes, allowing enhanced machining accuracy, and gate array control card components which allows improved reliability by using less cables and parts.

This series of drives offers a pair of seven segment displays to clearly display alarms and allow easy readability for the user, in the case of a unit alarming out.

When assessing the functionality of the Mistubishi MR-S11/MR-S12 AC Servo Drive Series, Our technician's employ a basic four step troubleshooting process:

    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 mega ohm meters, as well as any other necessary tools we need 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 performance of the repaired product when it arrives back with the customer.

Repair Process for Mitsubishi MR-S11 and MR-S12 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

On the MR-S11 and MR-S12 units, the control board and gate board are required to be removed in order to static check the unit. We do not recommend doing this unless the person checking is experienced as improper handling can result in damages.

DC Bus Capacitor Check

Upon removal of the control and gate board, this opens up a board with many screws connecting to different components. The DC bus capacitor has a round, dashed outline with two screws labeled ‘+’ and ‘-‘. This can be checked using a multimeter set to the capacitance setting. This value will need to be verified with the value printed on the capacitor itself.

Diode Bridge Check

The diode bridge is denoted with a sort of ‘U’ shaped screw layout and has 5 terminal screws on it. This is located near the bus capacitor. This can be checked using the diode check function on a multimeter. The layout of the screws will show which screw terminals relate to the positive and negative. It will look like two rows or columns based on how it is viewed, and one set will have 3 screws back to back whereas the other will have a screw with a space and then another screw. The row/column with the space will be the positive and negative terminals which can be used to check the diodes with the multimeter. Using the positive or negative lead with the respective screw and then using the other lead on each of the 3 screws on the other row should result in roughly a 0.45V reading, if the components are good.

Output Module Check

The output modules on these units can be tested by use of a digital multimeter with diode checking capabilities. Our technicians are also equipped with huntron devices further verify their integrity.

Positive Lead Negative Lead Reading
U Positive Bus Screw 0.39V-0.42V
V Positive Bus Screw 0.39V-0.42V
W Positive Bus Screw 0.39V-0.42V
Negative Bus Screw U 0.39V-0.42V
Negative Bus Screw V 0.39V-0.42V
Negative Bus Screw W 0.39V-0.42V

Common Alarms for the Mitsubishi MR-S11 and MR-S12

Alarm Code Description Quick Checks
10
Under Voltage
A drop of voltage has been detected of the 3 phase 200/220 VAC
  • Verify incoming power phase to phase as well as to ground
  • Monitor incoming for any instantaneous power failures
30
Over Regeneration
Overheating of regeneration resistor is detected; repeated power cycling can cause this resistor to burn
  • Verify servo parameter ORT; 4680=regen resistor absent, 3010=regen resistor present
  • Verify accel/decel times; attempt to increase if needed
  • See page 10 in manual for checking of regen transistor
32
Overcurrent
Overcurrent has been detected flowing through the drive unit
  • Check cables for poor insulation
  • Perform mogohm test on motor (see video for a how-to)
  • Use "output Module Testing" to verify modules
  • Check for ground faults
46
Motor Overheat
The thermal protector in the motor has been activated
  • Check if motor is hot; attempt to reduce load
  • Verify cable connections
  • See link to manual below for extra troublshooting steps
54
Amp Overload
(MR-S12 only)
Current detected exceeded set level while operated beyond a definitive time
  • Reduce load, if applicable
  • Verify servo parameter MTY matches motor requirement
  • See full alarm list, page 25 of manual, for further steps
55
Emergency
The terminals B and R, which were short circuited, are open
  • Check between terminals B and R for continuity
  • Verify incoming power is not below operating specs
  • Check continuity of main contactor in drive for continuity

For a full list of Mitsubishi MR-S11 and MR-S12 alarm codes and troubleshooting checks, see manual:

https://s3.amazonaws.com/Icarus/DOCUMENTS/Mitsubishi_Alarms_Faults_3523.pdf

The list of common alarms listed above is a great starting point to troubleshooting this Mitsubishi Servo Drive Series.

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-S11 and MR-S12 AC Servo Drives

  • 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-S12-80B-E01 image MR-S12-80B-E01 is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Bad Capacitor(s), Bad Circuit Board Component(s), Bad Output Transistors/SCRs, Leaky Capacitors (Open, Corroded Traces)
Drive Type: MR-S AC Servo Drive
Axis Specification: 2 Axis
Output Capacity: 1kW/500W
Option card: no card

Mitsubishi MR-S11-100-E31 image MR-S11-100-E31 is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Leaky Capacitors (Open, Corroded Traces), Bad Capacitor(s), Bad Gate Section/Board, Excessive Dirt/Debris
Drive Type: MR-S AC Servo Drive
Axis Specification: 1 Axis
Output Capacity: 2kW
Option card: RF-312 for closed loop

Mitsubishi MR-S12-40A-Z33 image MR-S12-40A-Z33 is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Bad Capacitor(s), Bad Circuit Board Component(s), Bad Gate Section/Board, Leaky Capacitors (Open, Corroded Traces)
Drive Type: MR-S AC Servo Drive
Axis Specification: 2 Axis
Output Capacity: 500W/500W
Option card: RF-332 for absolute value detection

Mitsubishi MR-S11-080-E01 image MR-S11-080-E01 is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Bad Capacitor(s), Board Replacement Required, Leaky Capacitors (Open, Corroded Traces)
Drive Type: MR-S AC Servo Drive
Axis Specification: 1 Axis
Output Capacity: 1kW
Option card: no card

Mitsubishi MR-S11-80-E01 image MR-S11-80-E01 is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Excessive Dirt/Debris, Leaky Capacitors (Open, Corroded Traces)
Drive Type: MR-S AC Servo Drive
Axis Specification: 1 Axis
Output Capacity: 1kW
Option card: no card

Mitsubishi MR-S11-103-E01 image MR-S11-103-E01 is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Bad Capacitor(s), Bad Circuit Board Component(s), Leaky Capacitors (Open, Corroded Traces), Excessive Dirt/Debris
Drive Type: MR-S AC Servo Drive
Axis Specification: 1 Axis
Output Capacity: 2kW
Option card: no card

Mitsubishi MR-S12-33A-E01 image MR-S12-33A-E01 is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Bad Circuit Board Component(s), Bad Cooling Fans, Bad Gate Section/Board, Excessive Dirt/Debris, Leaky Capacitors (Open, Corroded Traces)
Drive Type: MR-S AC Servo Drive
Axis Specification: 2 Axis
Output Capacity: 200W/300W
Option card: no card

Mitsubishi MR-S11-300-E01 image MR-S11-300-E01 is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Bad Capacitor(s), Bad Gate Section/Board, Bad Output Transistors/SCRs, Board Replacement Required, Leaky Capacitors (Open, Corroded Traces)
Drive Type: MR-S AC Servo Drive
Axis Specification: 1 Axis
Output Capacity: 4.5kW
Option card: no card

Mitsubishi MR-S12-80A-Z33 image MR-S12-80A-Z33 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
Drive Type: MR-S AC Servo Drive
Axis Specification: 2 Axis
Output Capacity: 1kW/1kW
Option card: RF-332 for absolute value detection

Mitsubishi MR-S12-80B-Z33 image MR-S12-80B-Z33 is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Bad Capacitor(s), Bad Circuit Board Component(s), Bad Gate Section/Board, Bad Output Transistors/SCRs, Leaky Capacitors (Open, Corroded Traces)
Drive Type: MR-S AC Servo Drive
Axis Specification: 2 Axis
Output Capacity: 1kW/500W
Option card: RF-332 for absolute value detection

Mitsubishi MR-S12-40A-E01 image MR-S12-40A-E01 is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Bad Capacitor(s), Bad Circuit Board Component(s), Bad Magnetic Contactor, Relay, Leaky Capacitors (Open, Corroded Traces)
Drive Type: MR-S AC Servo Drive
Axis Specification: 2 Axis
Output Capacity: 500W/500W
Option card: no card

Mitsubishi MR-S12-80A-E01 image MR-S12-80A-E01 is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Bad Circuit Board Component(s)
Drive Type: MR-S AC Servo Drive
Axis Specification: 2 Axis
Output Capacity: 1kW/1kW
Option card: no card

Mitsubishi MR-S11-200-E01 image MR-S11-200-E01 is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Bad Capacitor(s), Bad Circuit Board Component(s), Bad Gate Section/Board, Bad Output Transistors/SCRs
Drive Type: MR-S AC Servo Drive
Axis Specification: 1 Axis
Output Capacity: 3.5kW
Option card: no card

Mitsubishi MR-S11-200-E31 image MR-S11-200-E31 is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Bad Gate Section/Board, Bad Output Transistors/SCRs, Excessive Dirt/Debris, Leaky Capacitors (Open, Corroded Traces)
Drive Type: MR-S AC Servo Drive
Axis Specification: 1 Axis
Output Capacity: 3.5kW
Option card: RF-312 for closed loop

Mitsubishi MR-S12-100A-E01 image MR-S12-100A-E01 is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Bad Circuit Board Component(s), Bad Gate Section/Board, Bad Output Transistors/SCRs, Excessive Dirt/Debris, Leaky Capacitors (Open, Corroded Traces)
Drive Type: MR-S AC Servo Drive
Axis Specification: 2 Axis
Output Capacity: 2kW/2kW
Option card: no card

Mitsubishi MR-S12-100B-Z33 image MR-S12-100B-Z33 is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Bad Capacitor(s), Bad Circuit Board Component(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: 2 Axis
Output Capacity: 2kW/1kW
Option card: RF-332 for absolute value detection

Mitsubishi MR-S12-80A-E31 image MR-S12-80A-E31 is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Bad Circuit Board Component(s)
Drive Type: MR-S AC Servo Drive
Axis Specification: 2 Axis
Output Capacity: 1kW/1kW
Option card: RF-312 for closed loop

Mitsubishi MR-S11-100-E01 image MR-S11-100-E01 is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Leaky Capacitors (Open, Corroded Traces)
Drive Type: MR-S AC Servo Drive
Axis Specification: 1 Axis
Output Capacity: 2kW
Option card: no card

Mitsubishi MR-S12-80C-E01 image MR-S12-80C-E01 is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Bad Capacitor(s), Bad Circuit Board Component(s), Bad Gate Section/Board, Leaky Capacitors (Open, Corroded Traces)
Drive Type: MR-S AC Servo Drive
Axis Specification: 2 Axis
Output Capacity: 80C
Option card: no card

Mitsubishi MR-S11-300-E31 image MR-S11-300-E31 is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Bad Capacitor(s), Bad Circuit Board Component(s), Bad Gate Section/Board, Bad Output Transistors/SCRs, Leaky Capacitors (Open, Corroded Traces)
Drive Type: MR-S AC Servo Drive
Axis Specification: 1 Axis
Output Capacity: 4.5kW
Option card: RF-312 for closed loop

Mitsubishi MR-S11-33-E01 image MR-S11-33-E01 is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Bad Capacitor(s), Leaky Capacitors (Open, Corroded Traces)
Drive Type: MR-S AC Servo Drive
Axis Specification: 1 Axis
Output Capacity: 200-300W
Option card: no card

Mitsubishi MR-S11-100-Z37 image MR-S11-100-Z37 is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Bad Capacitor(s), Bad Circuit Board Component(s), Leaky Capacitors (Open, Corroded Traces), Board Replacement Required
Drive Type: MR-S AC Servo Drive
Axis Specification: 1 Axis
Output Capacity: 2kW
Option card: Z37

Mitsubishi MR-S12-100A-E31 image MR-S12-100A-E31 is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Bad Circuit Board Component(s), Bad Fuse, Bad Magnetic Contactor, Relay, Bad Power Section/Board, Excessive Dirt/Debris, Leaky Capacitors (Open, Corroded Traces), No Display
Drive Type: MR-S AC Servo Drive
Axis Specification: 2 Axis
Output Capacity: 2kW/2kW
Option card: RF-312 for closed loop

Mitsubishi MR-S11-40-E01 image MR-S11-40-E01 is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Bad Regen Section
Drive Type: MR-S AC Servo Drive
Axis Specification: 1 Axis
Output Capacity: 500W
Option card: no card