23.08.2025 by Viktor Siebert
When Standard Is Not Enough: The Hidden Complexity Behind the Yaskawa SGDV-120AE1A
In the world of automation and CNC technology, Yaskawa SGDV Servopacks are known for their precision and reliability. But behind the seemingly simple model designation SGDV-120AE1A often lies hidden complexity, namely, the version number. And this version number can determine the success or failure of a device replacement.
What’s Behind the Model Code?
The SGDV-120AE1A is a Servopack from the SIGMA V series with a nominal output of 1.5 kW. Many machine manufacturers such as Mazak, Mori Seiki, Star, or Brother use this standard hardware but have it customized with special software and parameters tailored to their application. As a result, the nameplate shows not only the base model but an extended code such as:
SGDV-120AE1AY579AA
These additional characters represent the so-called version number, and they are critical. They indicate that the device is a customized variant – adapted to a specific machine architecture, communication protocols, parameters, and motor types.
Why a Standard Unit Won’t Work
Many machine operators or maintenance technicians believe they can replace a defective unit with a generic SGDV-120AE1A from the open market. A costly mistake. Here’s why:
- Standard units are generally not compatible with the specialized machine environment
- Parameterization via software is usually locked
- Communication with the motor or CNC control fails
- The unit simply refuses to operate
Even devices offered on platforms like eBay or AliExpress with nearly identical designations are, in most cases, relabeled standard units without the specific firmware or parameter configuration. These often come from returns, overstock, or general refurbishments and very rarely with the original application software.
Two Reliable Paths – If You Know How
At Industrypart, we have decades of experience with these customized versions. There are basically two proven ways to replace such a unit successfully:
- Convert a standard device into the required version
Through targeted component replacement, reprogramming, and firmware adaptation, we can transform a standard SGDV into a compatible unit. Technically challenging, but achievable as long as you know exactly which parts and programming are needed.
- Repair the original unit
The better option: We thoroughly inspect, clean, repair, and restore the original unit using genuine components and parameters. The result is a fully overhauled unit that is guaranteed to work with the specific application reliable and cost-effective.
Our conclusion:
A professional repair is safer and often far more economical than taking risks with unknown used equipment.
Our SGDV Sigma V Servopack Repair Process
Based on our certified workflow, we provide comprehensive service for SGDV units, including customized versions. Our process includes:
Incoming Inspection
- Visual inspection for damage, corrosion, or tampering
- Diagnosis with dedicated tools and software
- Logging of all alarms and fault messages
Cleaning and Discharging
- Ionized closed-loop cleaning
- Removal of particles, oils, fine dust, and coolant residues
- Safe discharging of residual voltages
Repair
- Replacement of IGBTs, capacitors, diodes, and damaged boards
- Installation of preventive components to extend service life
- Restoration of original firmware (if required)
Functional and Load Testing
- Test runs with original motors and real CNC profiles
- Monitoring of temperature and current under load
- Verification of all interfaces and safety features
Quality Assurance
- Final test with documented protocol
- Tamper-evident sealing
- Shipment in ESD-safe packaging with test report
Information about the mentioned Servopack: SGDV-120AE1AY579AA
Further details on our Yaskawa repairs can be found here: Yaskawa Sigma V Repair
📞 Feel free to contact us if you have any questions regarding your Yaskawa drive technology. Our team will be happy to assist you.
Device Specifications
| Parameter | Value |
|---|
| Model | SGDV-120AE1AY579AA |
| Input Voltage (Main) | 3PH 200–230 V, 50/60 Hz |
| Input Current (Main) | 7.3 A |
| Input Voltage (Control) | 1PH 200–230 V, 50/60 Hz |
| Input Current (Control) | 0.25 A |
| Output Voltage | 3PH 0–230 V, 0–400 Hz |
| Output Current | 11.6 A |
| Output Power | 1.5 kW |
| Ambient Temperature | 0–55 °C |
| Protection Rating | IP10 |
| Manufacturer | Yaskawa Electric Corporation, Japan |
Operating Environment and Compatibility
This specialized version of the SGDV Servopack is designed for OEM applications and only functions when paired with specific motors and software provided by the machine manufacturer. Typical applications include CNC turning centers, machining centers, or custom-built production machinery requiring high dynamics and precise positioning.
Important: Standard units such as the SGDV-120AE1A are not compatible with the Y579AA version, due to:
- Proprietary firmware
- Locked parameter settings
- Application-specific motor pairing
Functional Description:
The SGDV-120AE1AY579AA is a digital servo amplifier from the Sigma V series designed for precision control of servo motors in real-time motion systems. It regulates speed, torque, and position using:
- Encoder feedback
- Power stage with IGBT technology
- Interface to CNC controllers
Configuration is locked and customized by the OEM, preventing unauthorized parameter modification or use with standard Yaskawa software tools.
Alarm Codes and Troubleshooting
Below are ten common alarms including their descriptions and recommended countermeasures:
| Alarm Code | Description | Cause | Recommended Action |
|---|
| A.100 | Overcurrent or heat sink overheat | Short circuit, overload, IGBT failure | Check wiring, replace motor or IGBT module |
| A.300 | Regeneration error | Missing or misconfigured brake resistor | Check wiring and parameters |
| A.320 | Regenerative overload | Incorrect system design | Modify load or adjust resistor configuration |
| A.400 | Overvoltage | Excessive power input | Stabilize power source |
| A.410 | Undervoltage | Power drop or brownout | Improve or stabilize input supply |
| A.510 | Overspeed | Excessive command input | Adjust command parameters |
| A.710 | Overload (high load) | Load exceeds rated torque | Reduce load or improve cooling |
| A.830 | Absolute encoder battery error | Battery depleted or disconnected | Replace battery |
| A.C90 | Encoder communication error | Loose or damaged cable | Check encoder wiring and shielding |
| A.d00 | Excessive position error | Encoder misconfiguration or signal noise | Check encoder and parameter Pn520 |
Internal Components
| Component Name | PCB Part Number | Quantity |
|---|
| Control Board | SGDV-IFAE1B | 1 |
| Interface Board | SGDV-CD120AAA | 1 |
| Power Board | SGDV-CB120AAA | 1 |
| Power Supply Board | SGDV-CC120AAA | 1 |
| Power Module | (not specified) | 1 |
| Option Module (Add-on) | SGDV-OCA01A | 1 |