Precision Zone Expertly Repairs Drives-AC Spindle Mitsubishi FR-SGJ

Here at Precision Zone, one of our specialties is the repair services of AC spindle drive units. One series that we often work on is the FR-SGJ series offered through Mitsubishi.

The FR-SGJ series of spindle drives are one of the few that Mitsubishi has to offer. External discharge resistors are used in this series to effectively discharge excess energy during regenerative braking. This series is offered for a three-phase, 200V input and has output capacities ranging from 750W (0.75kW) up to 7.5kW. There are also two main control methods, standard analog speed and digital I/O as well as a standard bus-line connection type. The application in which the unit is being used for will usually determine which form of control method is required.

A few option cards are available also, one for orientation and one for digital inputs. These again will only be required based on the application, as the standard for this series is without the card. The group of 7-segment displays on the control board makes it easy to go in and check parameters, check monitoring functions, and see fault codes if they occur.

When assessing the functionality of a drive, our repair team typically 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 FR-SF AC Spindle Drive Units

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 Module Testing

Due to extra components and the DC bus not being very easily accessible, on-site checking of input modules is not recommended. Output modules can be checked, mentioned below, but are still a bit difficult if unfamiliar with the unit.

Output Module Testing

Accessing the positive and negative DC bus requires probing from the side below the top control card, or removal of the top card to have a clear view of the points. Using a multimeter with a diode checking capability and the chosen method above, the large DC bus capacitor is labeled near the screw terminals on the lower board. Following the probe locations below, output modules can be checked for failure.

Positive Lead Negative Lead Reading
U '+' Screw Terminal 0.35V-0.42V
V '+' Screw Terminal 0.35V-0.42V
W '+' Screw Terminal 0.35V-0.42V
'-' Screw Terminal U 0.35V-0.42V
'-' Screw Terminal V 0.35V-0.42V
'-' Screw Terminal W 0.35V-0.42V

Mitsubishi FR-SGJ Spindle Drive Common Alarms

List of Alarms

Alarm Code Description Checks
AL 32
OC
Current which is larger than the specific maximum has been detected flowing through the FR-SGJ unit
  • Check cables for pooer insulation
  • Perform Megohm test on motor
  • Use "Output Module Testing" test to verify modules
AL 23
OSE
True motor speed is excessively different from the commanded speed
  • Veify motor power and feedback wiring
  • Verify parameter #2 - motor constant (MSL)
  • Motor encoder may be faulty
  • Swap in a known working unit, if applicable
AL 30
GF
A ground fault has been detected on the putput of the drive
  • Check motor or wire for ground fault
  • Check input/output terminals to ground for leakage
  • Replace drive

For a full list of Mitsubishi spindle drive alarm troubleshooting, see manual below:

https://s3.amazonaws.com/Icarus/DOCUMENTS/Mitsubishi_Alarms_Faults_82.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.

Precision Zone Repair Benefits for Mitsubishi Spindle 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 FR-SGJ-2-7.5K-BR image FR-SGJ-2-7.5K-BR is an
Drives-AC Spindle manufactured by Mitsubishi
Discovered issues: Bad Output Transistors/SCRs
Drive Type: FR-SGJ AC Spindle Motor
Power Supply: 200V
Output Capacity: 7.5kW
Series: Standard Series, Bus-line connection type
Card Type: SGJ-OR Card
Panel Installation Type: Panel Installation Type (Blank)

Mitsubishi FR-SGJ-2-3.7K-ARC image FR-SGJ-2-3.7K-ARC is an
Drives-AC Spindle manufactured by Mitsubishi
Discovered issues: Bad Circuit Board Component(s), Bad Cooling Fans, Bad Magnetic Contactor, Relay, Excessive Dirt/Debris, Leaky Capacitors (Open, Corroded Traces)
Drive Type: FR-SGJ AC Spindle Motor
Power Supply: 200V
Output Capacity: 3.7kW
Series: Standard Series, Analog speed command and digital I/O type
Card Type: SGJ-OR Card
Panel Installation Type: Middle Panel Installation Type

Mitsubishi FR-SGJ-2-7.5K-A image FR-SGJ-2-7.5K-A is an
Drives-AC Spindle manufactured by Mitsubishi
Discovered issues: Bad Circuit Board Component(s), Bad Gate Section/Board, Bad Output Transistors/SCRs, Bad Power Board, Leaky Capacitors (Open, Corroded Traces)
Drive Type: FR-SGJ AC Spindle Motor
Power Supply: 200V
Output Capacity: 7.5kW
Series: Standard Series, Analog speed command and digital I/O type
Card Type: No Card (blank)
Panel Installation Type: Panel Installation Type (Blank)

Mitsubishi FR-SGJ-2-1.5K-BR image FR-SGJ-2-1.5K-BR is an
Drives-AC Spindle manufactured by Mitsubishi
Discovered issues: Bad Gate Section/Board, Bad Output Transistors/SCRs
Drive Type: FR-SGJ AC Spindle Motor
Power Supply: 200V
Output Capacity: 1.5kW
Series: Standard Series, Bus-line connection type
Card Type: SGJ-OR Card
Panel Installation Type: Panel Installation Type (Blank)

Mitsubishi FR-SGJ-2-7.5K-B image FR-SGJ-2-7.5K-B is an
Drives-AC Spindle manufactured by Mitsubishi
Discovered issues: Bad Capacitor(s), Bad Circuit Board Component(s)
Drive Type: FR-SGJ AC Spindle Motor
Power Supply: 200V
Output Capacity: 7.5kW
Series: Standard Series, Bus-line connection type
Card Type: No Card (blank)
Panel Installation Type: Panel Installation Type (Blank)

Mitsubishi FR-SGJ-2-5.5K-AR image FR-SGJ-2-5.5K-AR is an
Drives-AC Spindle manufactured by Mitsubishi
Discovered issues: Bad Capacitor(s), Bad Circuit Board Component(s), Bad Output Transistors/SCRs
Drive Type: FR-SGJ AC Spindle Motor
Power Supply: 200V
Output Capacity: 5.5kW
Series: Standard Series, Analog speed command and digital I/O type
Card Type: SGJ-OR Card
Panel Installation Type: Panel Installation Type (Blank)