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Our Team Expertly Repairs Mitsubishi MR-S1 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-S1 AC Servo series.

Mitsubishi MR-S1 AC servo drives come in sizes ranging from 500W and can go up to 6kW. Additionally, the RF-312 option card can be used with these units allowing for closed loop functionality. This series can be used in systems utilizing Meldas M300 series NC and has had much of the analog circuitry replaced with digital circuitry, optimizing response repeatability and reliability.

The converter section of this unit has been compacted to be held within the frame reducing the overall footprint and amount of cables needed for this unit. This series of drives offer a pair of seven segment displays on the control card to clearly display alarms and allow easy readability for the user, in the case of a unit alarming out.

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

  • 1. Visual Overview
  • 2. Static Test
  • 3. Checks Under Power
  • 4. Alarm Code 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 performance of the repaired product when it arrives back with the customer.

Repair Process for Mitsubishi MR-S1 AC Servo Drives

Visual Overview Check

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-S1 units, the control board is 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 damage. If the unit has been previously been repaired through Precision Zone and falls within the warranty period, contact us before removing any board or components as this can potentially void the warranty.

Output Module Check

Upon removing the control card, the base is opened up and components can be viewed or checked. Certain MR-S1 models will have three separate transistor modules and others will have an integrated 6-in-1 module. The output modules on these units can be tested by use of the table below and 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 0.32V-0.42V
V Positive Bus Screw 0.32V-0.42V
W Positive Bus Screw 0.32V-0.42V
Negative Bus Screw U 0.32V-0.42V
Negative Bus Screw V 0.32V-0.42V
Negative Bus Screw W 0.32V-0.42V

MR-S1 Common Alarms

Alarm Code Description 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 phase 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 here on page 10 for checking of regen transistor
32
Overcurrent		 Overcurrent has been detected flowing through the drive unit
  • Check cables for poor insulation
  • Perform megaohm test on motor. Watch our video here for reference
  • Use “Output Module Testing” test 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 troubleshooting 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 alarm troubleshooting, visit the link below to view the manual: https://s3.amazonaws.com/Icarus/DOCUMENTS/Mitsubishi_Alarms_Faults_3693.pdf

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. For more information on these alarms as well as any other failures, please give us a call at 800-551-4420 or email us today!

Precision Zone Repair Benefits for Mistubishi AC Servo Drives
  • 1. FREE evaluation by expert technician includes:
  • Visual Inspection
  • Static Check
  • Power Tests
  • 2. FREE job estimate
  • 3. 12 month warranty on our parts and labor
  • 4. Flat Price
  • 5. Exchange Option
  • 6. Rush Service

Recently Repaired Products

Mitsubishi MR-S1-200-E31 image MR-S1-200-E31 is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Bad Capacitor(s), Bad Cooling Fans, Bad Gate Section/Board, Bad Magnetic Contactor, Relay, Bad Power Section/Board, Excessive Dirt/Debris, Multiple signs of previous repair
Drive Type: MR-S AC Servo Drive
Axis Specification: 1 Axis
Output Capacity: 4kW
Option card: RF-312 for closed loop

Mitsubishi MR-S1-100-E01 image MR-S1-100-E01 is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Bad Capacitor(s), Bad Cooling Fans, Bad Gate Section/Board, Bad Magnetic Contactor, Relay, Bad Output Transistors/SCRs, Bad Power Section/Board, Excessive Dirt/Debris, 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-S1-80-E01 image MR-S1-80-E01 is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Bad Capacitor(s), 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: 1 Axis
Output Capacity: 1kW
Option card: no card

Mitsubishi MR-S1-100-E31 image MR-S1-100-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: 1 Axis
Output Capacity: 2kW
Option card: RF-312 for closed loop

Mitsubishi MR-S1-300-E31 image MR-S1-300-E31 is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Bad Output Transistors/SCRs
Drive Type: MR-S AC Servo Drive
Axis Specification: 1 Axis
Output Capacity: 6kW
Option card: RF-312 for closed loop

Mitsubishi MR-S1-103-E01 image MR-S1-103-E01 is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Bad Cooling Fans, Bad Regen Resistor/s, Bad Regen Section
Drive Type: MR-S AC Servo Drive
Axis Specification: 1 Axis
Output Capacity: 2kW
Option card: no card

Mitsubishi MR-S1-80-E31 image MR-S1-80-E31 is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Bad Capacitor(s), 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: 1 Axis
Output Capacity: 1kW
Option card: RF-312 for closed loop

Mitsubishi MR-S1-300-E01 image MR-S1-300-E01 is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Bad Transformer, No Display
Drive Type: MR-S AC Servo Drive
Axis Specification: 1 Axis
Output Capacity: 6kW
Option card: no card

Mitsubishi MR-S1-103-E31 image MR-S1-103-E31 is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Bad Magnetic Contactor, Relay, Bad Gate Section/Board
Drive Type: MR-S AC Servo Drive
Axis Specification: 1 Axis
Output Capacity: 2kW
Option card: RF-312 for closed loop

Mitsubishi MR-S1-83-E31 image MR-S1-83-E31 is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Bad Regen Resistor/s, Bad Regen Section, Excessive Dirt/Debris, Leaky Capacitors (Open, Corroded Traces)
Drive Type: MR-S AC Servo Drive
Axis Specification: 1 Axis
Output Capacity: 1kW
Option card: RF-312 for closed loop

Mitsubishi MR-S1-40-E01 image MR-S1-40-E01 is an
Drives-AC Servo manufactured by Mitsubishi
Discovered issues: Leaky Capacitors (Open, Corroded Traces), Bad Magnetic Contactor, Relay
Drive Type: MR-S AC Servo Drive
Axis Specification: 1 Axis
Output Capacity: 500W
Option card: no card