Initial Condition and Symptoms

The Yaskawa SGMGS-05A5W-SE12 was sent to industrypart GmbH for a complete standard overhaul. The motor showed minor bearing wear and inconsistent encoder feedback. It had been operating in a CNC axis under continuous load for several years, typical of high-duty machine environments.

Mechanical and Electrical Overhaul

After incoming inspection, the motor was fully disassembled. The stator windings were cleaned, dried, and checked using a high-voltage insulation test. Bearings, seals, and connectors were replaced preventively.
The UTSAH-B17BE encoder showed signal irregularities and was replaced with a new, factory-calibrated unit. The encoder was precisely aligned and adjusted to the motor shaft before re-assembly.

Load Test Station and Functional Verification

A key part of our quality assurance is the dedicated load test station for servo motors, developed in-house for precision verification.
This test bench can test servo motors up to 4.4 kW under controlled mechanical load. For Sigma-V motors, we use the original Yaskawa SGDK-050505AEA-V Servopack, ensuring identical control parameters and feedback conditions to factory standards.

During testing, parameters such as current, torque, temperature, signal shape, and encoder feedback are continuously monitored. The test proceeds through several stages from no-load diagnostics to full-load verification. All results are automatically recorded in our database for complete traceability.

Testing under load is essential: only real operating conditions reveal whether a motor performs correctly after repair. Simulated torque and speed changes verify that the motor maintains thermal stability, electrical symmetry, and accurate position feedback even under continuous stress.

Test Results and Final Acceptance

After a 60-minute full-load endurance test, the motor showed perfect results smooth running, stable temperature, precise torque response, and fault-free encoder signals.
Final inspection confirmed full restoration of mechanical and electrical properties. The motor was then painted, labeled, and released for shipment. A full measurement report and load curve were stored in our test documentation archive.

Outcome and Customer Benefit

Through systematic overhaul, preventive replacement, and real-load testing, the motor now performs exactly like a new unit. The combination of original Yaskawa hardware and structured test documentation guarantees reliability, traceability, and long-term performance at a fraction of the cost of a new motor.

Preventive Maintenance Recommendations

Conclusion

The repair and testing of the Yaskawa SGMGS-05A5W-SE12 demonstrate how critical load testing is for reliable quality assurance. Only by simulating real-world mechanical and electrical stress can we confirm full restoration of performance after repair.
Our custom-built load test station, equipped with original Yaskawa technology, provides repeatable measurements, complete documentation, and the highest level of confidence that every overhauled servo motor performs to factory standards.

This approach ensures long-term precision, reliability, and reduced downtime for our customers a perfect example of how quality and sustainability go hand in hand in industrial repair.

Information about the mentioned Servopack and Servomotor:

• Yaskawa AC Servo Motor SGMGS-05A5W-SE12
• Encoder Yaskawa UTSAH-B17BE
• Servopack SGDK-050505AEA-V

More information about our Yaskawa repairs can be found here.

📞 Feel free to contact us if you have any questions regarding your Yaskawa drive technology. Our experienced team is always ready to assist you.

Technical Data of the AC Servo Motor (SGMGS‑05A5W‑SE12)

Operating Environment & Compatible Devices

The Yaskawa SGMGS-05A5W-SE12 is typically used in STAR lathes, Matsuura machining centers, and other CNC production systems equipped with Siemens or Yaskawa controls.
It is compatible with SGDK-series servo amplifiers and designed for ambient conditions of 0–40 °C and 20–80 % relative humidity (non-condensing).
An optional 24 V brake can be installed for vertical axis applications.

Functional Description

The Yaskawa SGMGS-05A5W-SE12 is a three-phase permanent-magnet synchronous servo motor with a high-resolution UTSAH-B17BE encoder.
It operates in combination with the SGDK-050505AEA-V Servopack, which uses field-oriented vector control to manage current, torque, speed, and position in real time.
This combination ensures highly dynamic response and outstanding precision, ideal for machine tools and robotics.

Integrated protective functions include:

• Over-current, ground fault, and short-circuit protection
• Under-voltage monitoring
• Overload and over-temperature shutdown
• Regeneration and communication fault detection

These features guarantee reliable performance in demanding industrial environments.

Alarms & Troubleshooting

Components