A servo motor can still run even when its bearings are worn. A Yaskawa SGMAH-02AAA61D-OY from our workshop illustrates this: incoming electrical measurements were acceptable and the motor ran, but the inspection also identified worn ball bearings. A short test run alone is therefore insufficient to assess the condition of a used servo motor.

What does the SGMAH-02AAA61D-OY do?

The SGMAH-02AAA61D-OY is an AC servo motor. Together with a compatible servo amplifier and encoder feedback, it forms a controlled drive. Selecting a replacement requires checking the complete model designation, electrical and mechanical configuration, and compatibility with the existing drive. A similar base model number is not sufficient confirmation.

Technical data from the original nameplate

These values were read from the original nameplate of the motor serviced. They do not replace a compatibility check for the actual machine and drive configuration.

Which signs deserve attention?

Unusual running noise, vibration or changes in temperature may justify investigation. These symptoms alone do not establish a bearing fault. The coupling, driven machinery, alignment and operating conditions also need consideration.

A practical troubleshooting sequence

Start by recording the complete motor designation, servo amplifier model and fault symptoms. Note whether the problem occurs on starting, during a particular movement or only after warming up. Before work, the equipment must be properly isolated and secured against restart. Stored energy and the manufacturer’s instructions must be considered.

Next come a visual inspection and appropriate mechanical and electrical condition checks. Mounting, shaft, coupling, cables and connectors all deserve attention. Evaluate the findings together: acceptable electrical results do not rule out mechanical wear. Test methods and limits must suit the specific motor, encoder and drive.

A final functional test requires a compatible servo amplifier. This does not automatically rule out faults elsewhere in the machine. The machine configuration and installation conditions must also be checked before recommissioning.

Workshop example: overhaul and testing at industrypart

This SGMAH-02AAA61D-OY ran during incoming inspection and its electrical measurements were acceptable. Mechanical inspection nevertheless identified worn ball bearings. The motor was dismantled, cleaned, treated to remove rust and dried. The mechanical assembly and encoder feedback were restored, and the cabling was reworked. After assembly and painting, the motor was tested with a servo drive.

The job was completed with the status “repaired and tested”.

Our test amplifier: Yaskawa SGDH-02AE

At industrypart, we test the SGMAH-02AAA61D-OY with the Yaskawa SGDH-02AE SERVOPACK. Yaskawa lists SGDH-02AE as the standard combination for SGMAH-02A. Replacement selection still requires checking the complete motor version, encoder, connections and machine configuration.

SGDH-02AE alarms related to the motor and encoder

The following reference describes possible SGDH fault indications, not alarms recorded in this repair. Check the amplifier version, firmware and operating mode. Absolute-feedback indications only apply to appropriately equipped and configured systems.

For A.C9, investigate wiring, connectors, interference, the encoder and the amplifier. An encoder alarm alone does not prove an encoder defect. Record when it occurs, the complete nameplate information and the cable routing. Battery or absolute-feedback work may require referencing according to the machine manufacturer’s instructions.

Overload and position deviation can also be associated with mechanical resistance or unsuitable drive settings. Worn bearings were confirmed in this workshop case; that finding does not establish that any particular alarm occurred.

Source: Yaskawa Sigma II User’s Manual, YEA-SIA-S800-32.2, standard combination p. 5-112, alarm reference pp. 9-40/9-41 and A.C9 troubleshooting p. 9-28.

Preventive measures during installation

Yaskawa’s Sigma II manual highlights correct alignment, permitted shaft loading and cable routing without tensile or bending stress. Keep dirt and moisture away from the motor. Operation requires a suitable servo amplifier; direct connection to the mains is not intended. Refer to the applicable manufacturer documentation for the specific installation.

Sources

Technical data: original motor nameplate. Findings and work performed: industrypart workshop records. General installation guidance: Yaskawa Sigma II User’s Manual, YEA-SIA-S800-32.2, Installation chapter.

Workshop video

Enquire about testing, overhaul or a replacement motor

Do you need your SGMAH-02AAA61D-OY inspected or require a replacement? Send the full model designation, a readable nameplate photograph, the servo amplifier model and a description of the symptoms. This helps us prepare a focused assessment.

Yaskawa SGMAH-02AAA61D-OY: product and repair enquiry

Troubleshooting by symptom

These are inspection directions, not confirmed diagnoses.