Yaskawa GA800 A.127 Fault — What It Means
The A.127 code does not match documented Yaskawa GA800 fault formats. GA800 drives typically display faults as short alphanumeric codes such as oC (overcurrent), Uv (undervoltage), or CPF (control fault), not decimal codes like A.127. This suggests the display may be misread, the code may refer to a parameter alarm or monitor item rather than a fault, or the drive may actually be a different Yaskawa model family where numbering conventions differ.
Before attempting repairs, confirm the exact text shown on the keypad including any letters, numbers, or symbols. Access the fault history menu on the drive keypad or use Yaskawa DriveWizard software to retrieve the last recorded alarm and operating conditions at the time of the fault. Verify the drive nameplate to confirm the model is indeed a GA800 and not a GA700, A1000, or other series. Once you have the correct fault code, cross-reference it with the fault table in your drive’s manual to identify the specific cause and the manufacturer’s recommended corrective action.
Before You Replace Anything
Technicians sometimes replace the main control board or power module when the fault is actually a wiring error, incorrect parameter setting, or mechanical load binding. Always verify the exact fault code from the history menu and inspect motor wiring, parameter configuration, and mechanical coupling before ordering boards.
Common Causes
- Misread or transposed display (~40%) The decimal point or digits may have been read incorrectly, or the alarm is a parameter number or monitor value rather than a fault code.
- Wrong model family (~30%) The drive may be a GA700, A1000, or another Yaskawa series that uses different fault numbering, so the code table in the GA800 manual will not match.
- Custom parameter alarm (~20%) Some integrators program custom alarms or warnings that display non-standard codes, especially when the drive is networked or uses application macros.
- Communication or keypad glitch (~10%) A temporary display error or corrupted keypad firmware can show garbled codes that do not correspond to any real fault in the drive’s memory.
Quick Diagnosis
Answer these to narrow it down fast.
Does the keypad show a blinking or steady code, and can you enter the fault history menu?
No: The keypad may be faulty or disconnected. Check the ribbon cable between the keypad and control board, and try resetting power to the drive to clear temporary display errors.
Does the drive nameplate confirm the model is GA800?
No: Obtain the correct manual for the actual model (GA700, A1000, etc.) and use that fault table. Code meanings and diagnostics differ between Yaskawa families.
Is the drive connected to a fieldbus network or PLC?
No: The code is more likely a standard drive fault. Use DriveWizard to read out the internal fault log and any parameter mismatches or overload conditions.
Step-by-Step Fix
- Power down and lock out the drive using your facility’s lockout-tagout procedure. Wait at least five minutes for DC bus capacitors to discharge before opening any covers.
- Record the exact alarm text from the keypad. Write down every character, including dots, dashes, and any blinking segments. Take a photo of the display if possible.
- Enter the fault history menu by pressing the menu or monitor key on the keypad, then scroll to alarm history or fault log. Note the fault code, the parameter that triggered it, and the timestamp.
- Cross-reference the code in the GA800 instruction manual’s fault and alarm table. If A.127 does not appear, check the parameter list to see if 127 refers to a monitor or tuning value rather than a fault.
- Verify the drive model on the nameplate. Confirm the series (GA800) and firmware revision. If the model is different, obtain the correct manual from Yaskawa’s website.
- Inspect motor and control wiring for loose connections, damaged insulation, or incorrect terminal assignments. Check that encoder or feedback cables are shielded and routed away from power cables.
- Contact Yaskawa technical support with the drive serial number, exact keypad display, fault history printout, and any recent parameter changes. They can confirm whether A.127 is a valid code for your firmware version or suggest next diagnostic steps.
Parts Often Needed
| Part | Notes |
|---|---|
| Yaskawa keypad (JVOP‑180 or equivalent) | Amazon | Only if the display is physically damaged or the ribbon cable test confirms keypad failure. |
| GA800 instruction manual (printed or PDF) | Amazon | Essential for matching the exact fault code to the correct diagnostic procedure and parameter list. |
When to Call a Pro
Call a qualified drives technician or Yaskawa-certified service partner whenever you cannot confirm the exact fault code from the manual, when the drive is part of a networked or safety-rated system, or when you lack the test equipment to measure DC bus voltage, gate signals, or encoder feedback. High-voltage work on VFD power modules and control boards requires specialized training and insulated tools. If the drive has been modified with custom programming or fieldbus integration, the original system integrator or machine builder should diagnose non-standard codes before you replace any hardware.
Rough cost: A pro service call runs about $150–400.