Yaskawa A1000 AL-10 Fault — What It Means
The code AL-10 does not exist in official Yaskawa A1000 documentation. You are probably seeing the ALM indicator (which simply means a fault is active) alongside a specific fault code, or you may be looking at oPE10, the only A1000 fault ending in 10. The oPE10 code means V/f Data Setting Error: one or more parameters that define the motor’s voltage-to-frequency curve are set incorrectly or conflict with each other, so the drive cannot start the motor in V/f control mode.
Common conflicts include setting the Base Frequency higher than the Max Frequency, entering a Max Voltage that does not match the motor nameplate, or switching the motor control method to a mode that does not support the configured V/f pattern. If you see a different number after ALM, consult your A1000 manual to identify the exact fault.
Before You Replace Anything
Technicians sometimes replace the control board or main PCB when oPE10 appears, but this is a configuration error, not a hardware failure. Always review and correct parameters E1-04, E1-06, E1-07, E1-09, and E1-11 before ordering any circuit board.
Common Causes
- Conflicting frequency parameters (~45%) Base Frequency (E1-07) is set higher than Max Frequency (E1-06), or Intermediate Frequency (E1-11) exceeds the max limit.
- Max Voltage mismatch (~30%) Parameter E1-04 does not match the motor’s rated voltage (230V, 400V, or 480V), creating an invalid V/f curve.
- Motor control method incompatible (~15%) C1-02 is set to Open Loop Vector or Closed Loop Vector, which does not support the specific V/f pattern configured in E1-09 and E1-11.
- Intermediate point values out of order (~8%) Intermediate Voltage (E1-09) or Intermediate Frequency (E1-11) creates a non-linear or invalid curve that violates the allowable range.
- Motor 2 parameter error in dual-motor setup (~2%) If using two motors, the corresponding E2-04, E2-06, or E2-07 parameters for Motor 2 have the same conflicts.
Quick Diagnosis
Answer these to narrow it down fast.
Does the display show oPE10, or does it show ALM with a different number?
No: You have a different fault code. Look up the number shown after ALM in your A1000 manual to identify the actual problem.
Is parameter E1-07 (Base Frequency) less than or equal to E1-06 (Max Frequency)?
No: Lower E1-07 so it does not exceed E1-06, then clear the fault and test.
Is parameter C1-02 set to 0 (V/f Control)?
No: Change C1-02 to 0 if you need V/f control, or adjust the V/f parameters to match the selected control method.
Step-by-Step Fix
- Confirm the fault code by pressing the keypad menu button and reading the full alphanumeric code (oPE10, not just ALM).
- Check C1-02 (Motor Control Method) and set it to 0 (V/f Control) if you intend to use voltage-to-frequency control.
- Navigate to E1-04 (Max Voltage) and verify it matches the motor nameplate voltage (for example, 460V for a 460V motor).
- Compare E1-06 (Max Frequency) and E1-07 (Base Frequency) to confirm E1-07 is less than or equal to E1-06 (standard is 60Hz for both, or 50Hz in some regions).
- Review E1-09 (Intermediate Voltage) and E1-11 (Intermediate Frequency) to confirm they fall between zero and the max values and create a linear curve.
- Clear the fault by pressing the STOP/RESET button or cycling power to the drive.
- Run a test in V/f mode by commanding a forward run and observing the motor for smooth acceleration without re-triggering oPE10.
Parts Often Needed
| Part | Notes |
|---|---|
| Control keypad (JVOP-180 or equivalent) | Amazon | Only if the keypad is damaged and you cannot access parameters to correct them (rare). |
| Main control PCB (A1000 series) | Amazon | Only if parameter memory is corrupted and factory reset does not restore function (extremely rare for oPE10). |
When to Call a Pro
Call a qualified electrician or drives technician if you are unfamiliar with VFD parameter programming, if the drive is part of a critical process control system, or if clearing the parameter conflicts does not resolve oPE10 after multiple attempts. A professional can perform a full parameter audit, back up your configuration, and check for firmware corruption or main-board memory faults. Also call a pro if the drive displays a different fault code (not oPE10) or if you need to integrate the A1000 with a PLC or SCADA system that requires specialized communication setup.
Rough cost: A pro service call runs about $150–$350 for a service call to reprogram parameters.