Yaskawa GA800 E81 Fault Code — What It Means
The E81 fault code does not appear in the indexed Yaskawa GA800 maintenance and troubleshooting documentation. It may be a display misread (such as Er-21 or another similar-looking code), a variant specific to a custom firmware revision, or a code from a different Yaskawa drive series. Yaskawa documentation directs technicians to read the exact fault from the keypad event log, then cross-reference it in the official manual to identify the fault category (such as overcurrent, overvoltage, communication loss, or sensor error) and follow the corresponding diagnostic flowchart.
Because the GA800 manual does not define E81, the safest approach is to confirm the code display, inspect the application context (input power quality, motor leads, control wiring, encoder or safety I/O if used), and contact Yaskawa technical support with the drive model number, specification code, serial number, and the exact fault code for an authoritative interpretation.
Before You Replace Anything
Technicians sometimes replace the control board or main power module before verifying the exact fault definition and checking input power, loose connections, or encoder wiring. Always confirm the code in the manual and perform voltage and wiring checks first.
Common Causes
- Misread or transposed display The keypad may show a code that looks like E81 but is actually Er-21, E8.1, or another fault with a similar character pattern.
- Custom or firmware-specific code Some Yaskawa drives receive application-specific firmware that introduces fault codes not listed in the standard manual.
- Input power disturbance Voltage sags, phase loss, or ground faults can trigger unlisted or generic fault codes that require Yaskawa support to decode.
- Encoder or feedback wiring fault Open or shorted encoder leads, incorrect pulse count, or noise on the feedback circuit can produce non-standard fault displays.
- Control-board or memory corruption A failing EEPROM or corrupted parameter set may cause the drive to display an undefined or garbled fault code.
- Communication or network error If the drive is networked (Modbus, Profibus, EtherNet/IP), a fieldbus timeout or configuration mismatch may register as an unusual fault.
Quick Diagnosis
Answer these to narrow it down fast.
Does the keypad display the fault clearly as E81, with no flicker or partial segments?
No: The display may be damaged or the fault code may be transient. Power-cycle the drive, record any new codes, and inspect the keypad ribbon cable.
Is the drive connected to an encoder, resolver, or external safety circuit?
No: Focus on input power quality, motor leads, and control I/O. Measure incoming line voltage at L1, L2, L3 and check for phase imbalance or ground faults.
Does the fault appear immediately at power-up, or only when a run command is given?
No: Run-command faults often relate to motor configuration, load condition, or feedback mismatch. Review acceleration time, V/f curve, and current-limit parameters.
Step-by-Step Fix
- Power down and lock out the drive at the main disconnect, then wait for the DC bus capacitors to discharge (at least five minutes or until the charge LED is off).
- Photograph the keypad display and write down the exact fault code, including any decimal points, spaces, or additional characters that may distinguish E81 from a similar code.
- Retrieve the fault history from the keypad menu (consult the GA800 operation manual for the alarm-log navigation path) and note whether other faults occurred before or after E81.
- Inspect all wiring terminations at the input power terminals (L1, L2, L3), motor output terminals (U, V, W), control I/O, and encoder or feedback connectors for looseness, corrosion, or char marks.
- Measure incoming line voltage with a true-RMS multimeter at L1-L2, L2-L3, and L3-L1 to confirm three-phase balance within 2 percent and verify that voltage matches the drive nameplate rating.
- Check encoder or feedback signals if the application uses closed-loop control. Verify wiring pinout, shield grounding, and that parameter groups for encoder type and pulse count match the installed hardware.
- Contact Yaskawa technical support with the drive model number, specification code (the full catalog number from the nameplate), serial number, exact fault code, application type, and length of service to obtain an authoritative fault definition and recommended corrective action.
Parts Often Needed
| Part | Notes |
|---|---|
| Yaskawa GA800 control board | Amazon | Only order after Yaskawa support confirms a board fault; specify your exact drive model and serial number when ordering. |
| Yaskawa GA800 cooling fan | Amazon | Field-replaceable per the maintenance manual; check fan rotation and bearing noise if the drive has been in service for several years. |
When to Call a Pro
Call a qualified industrial electrician or Yaskawa-certified technician if you cannot find E81 in your printed manual, if the fault persists after wiring checks and power-quality verification, or if you lack the test equipment to safely measure high-voltage DC bus and gate-driver signals. Yaskawa technical support requires the drive model number, specification code, serial number, and exact fault code to provide a diagnosis. Do not replace the control board or power module without confirming the fault definition, because input power issues, encoder wiring errors, and parameter mismatches often mimic internal hardware failures and will damage a new board if the root cause is not corrected first.
Rough cost: A pro service call runs about $150–500 depending on whether the issue is wiring, a control board, or a power module.