Yaskawa GA800 A.144 Fault — What It Means
A.144 is not documented as a standard alarm code in Yaskawa GA800 manufacturer materials. The code you are seeing may be misread from the keypad display, or it may belong to a different Yaskawa drive family. Yaskawa drives do use alphanumeric fault codes, but the specific meaning of A.144 for the GA800 cannot be confirmed without the drive’s technical manual. Similar-looking codes such as A.14 or oFA14 (Receive Abort Error) exist in other Yaskawa series and may be what is actually displayed.
Because the exact meaning is not verified, troubleshooting should follow the general Yaskawa alarm workflow: record the exact displayed code and alarm history, inspect all wiring and terminations for damage or loose connections, isolate the motor and load to determine whether the fault follows the motor or stays with the drive, check encoder and option-card connections if installed, and replace only the component that testing confirms as failed. Do not guess at repairs until the fault path is confirmed.
Before You Replace Anything
Technicians sometimes replace the entire drive or control board when the real cause is a damaged motor cable, shorted encoder wire, or loose option-card connector. Always isolate and test each component before ordering expensive parts.
Common Causes
- Misread or incorrect fault code (~30%) The keypad may be displaying a similar code such as A.14 or the technician may have recorded the wrong number.
- Damaged or shorted motor cable (~25%) Output wiring with insulation damage, a short to ground, or a loose termination can trigger feedback and communication alarms.
- Encoder or feedback-card fault (~20%) A loose encoder connector, damaged encoder cable, or failed encoder option card will cause position or communication errors.
- Faulty option card or communications module (~15%) An improperly seated or defective fieldbus, DeviceNet, or Modbus card can generate alarm codes that resemble A-series faults.
- Control-board or internal drive circuit failure (~10%) A damaged feedback circuit, power-supply fault, or control-board component failure inside the drive can produce undefined or intermittent codes.
Quick Diagnosis
Answer these to narrow it down fast.
Does the drive display show exactly A.144, with no other characters or symbols?
No: Record the exact alphanumeric string as shown, including any leading letters or decimal points, then look it up in the alarm-history menu and the technical manual.
Does the alarm clear when you disconnect the motor and encoder cables and reset the drive?
No: The fault is internal to the drive or related to an option card or control wiring. Check all option-card seating and control-terminal connections.
Is an encoder or communications option card installed in the drive?
No: Focus troubleshooting on main power wiring, motor cable integrity, and the drive control board.
Step-by-Step Fix
- Power down and lock out the drive at the main disconnect, then wait for all status LEDs to go dark and verify zero voltage at the drive input and output terminals with a multimeter.
- Record the exact fault code as it appears on the keypad display, including any letters, numbers, and decimal points, and review the alarm-history menu to see if the code has occurred before or if other codes are logged.
- Inspect all wiring terminations at the drive input, output, and control terminals for loose screws, burned insulation, or signs of arcing, and check motor-cable insulation with a megohmmeter if available.
- Disconnect the motor and encoder cables from the drive output and feedback terminals, then power up the drive with no load and attempt to clear the fault by pressing the reset button or cycling power.
- Check option cards and communication modules by powering down, removing each card, inspecting the edge connector and slot for dust or damage, reseating the card firmly, and verifying that the card part number matches the drive model and firmware version.
- Test the motor and encoder separately by measuring motor winding resistance and insulation to ground, inspecting encoder cable continuity and shield grounding, and verifying that encoder supply voltage matches the encoder nameplate.
- Consult the GA800 technical manual alarm-code table for your specific firmware revision, and if A.144 is not listed or the fault persists after isolating all external components, contact Yaskawa technical support or replace the drive control board or entire drive assembly.
Parts Often Needed
| Part | Notes |
|---|---|
| Motor cable (shielded, VFD-rated) | Amazon | Match cable length and conductor gauge to the original; use continuous-shield construction and ground the shield at the drive end only. |
| Encoder cable and connector | Amazon | Verify pin count and shielding match the encoder and drive option-card specifications. |
| Option card (encoder, fieldbus, or communications module) | Amazon | Order by the exact Yaskawa part number printed on the failed card; confirm compatibility with your drive firmware version. |
| GA800 control board or complete drive assembly | Amazon | Required only if internal circuitry is confirmed failed; provide the drive nameplate model and serial number when ordering. |
When to Call a Pro
Call a qualified drive technician or Yaskawa-certified service provider if you cannot locate A.144 in your GA800 manual, if the fault persists after disconnecting all external wiring and option cards, or if you lack the tools to safely measure high voltage and motor insulation. Professional help is also necessary if the drive requires internal control-board replacement or firmware updates, or if the motor or encoder must be tested under load. A trained technician will have access to Yaskawa technical support, the correct fault-code database for your firmware revision, and the diagnostic equipment needed to isolate internal drive faults without risking further damage.
Rough cost: A pro service call runs about $200–800 depending on whether the fault is wiring, an option card, the motor, or internal drive circuitry.