Yaskawa Error Code A910 __link__ [BEST]

Troubleshooting Yaskawa Error Code A910: A Comprehensive Guide to Main Circuit Undervoltage

6. Improper Grounding or Motor Cable Faults

Although less direct, a short circuit to ground on the motor output (U, V, W) can sometimes cause a back-feed into the current detection circuit during the drive’s diagnostic phase.

Step 3: Inspect External Wiring and Grounding

  1. Disconnect the motor leads from drive terminals U, V, W.
  2. Power up the drive with no load attached.
  3. Does A910 still appear?
    • YES: The problem is internal to the drive.
    • NO: The problem is external (motor, cable, or grounding).
  4. If external, check:
    • Motor insulation resistance (Megger test).
    • Cable shielding and proper grounding (single-point ground).
    • Eliminate any VFD-rated cable damage.

Common Causes

  1. Excessive Load:

    • The load on the motor is too heavy (e.g., a machine jam, a conveyor belt rubbing against something, or a pump trying to push too much fluid).
    • The mechanical system requires more torque than the motor/drive can provide continuously.

  2. Incorrect Parameter Settings:

    • E2-01 (Motor Rated Current): If this parameter is set lower than the actual motor nameplate rating, the drive thinks the motor is overloading sooner than it actually is.
    • L3-02 (Stall Prevention Level): If this limit is set too low, the drive may trigger the warning during normal acceleration.

  3. Acceleration/Deceleration Issues:

    • Accelerating too fast (Acceleration time in C1-01 is too short) requires high inrush current, which can trigger this warning.

  4. Input Power Issues:

    • Low input voltage (brownout) causes the motor to draw more current to maintain power.

  5. Motor/Drive Mismatch:

    • Using a motor that is larger than the rated capacity of the inverter.

5. Aged or Faulty DC Bus Capacitors

Electrolytic capacitors have a finite lifespan—typically 5 to 10 years under normal operating temperatures. As capacitors dry out, their Equivalent Series Resistance (ESR) rises. They can no longer "hold" the DC voltage steady, especially under fluctuating loads. You will see A910 occur intermittently, often during load transients. yaskawa error code a910

4. Firmware Glitch or Corrupted Parameters

Rarely, a corrupted parameter set (especially after a poor upload/download operation) can misconfigure the current offset auto-calibration routine. This is more common after battery-backed memory failures.

What is A910?

A910 is an alarm (not a fatal fault). It indicates that the drive has detected a loss of current in one or more of the drive’s output phases (U, V, W) while the drive is running.

⚠️ If the alarm persists or occurs under load, the drive may trip on a more serious fault (e.g., LF, PF). Disconnect the motor leads from drive terminals U, V, W

Parameter Check

| Parameter | Setting | Note | |-----------|---------|------| | L8-05 | 1 (default) | Enables output phase loss detection. Set to 0 to disable (not recommended). | | L8-07 | 1 (default) | Output phase loss protection active. |

🔧 Temporarily disabling detection (L8-05=0) can help identify if the alarm is nuisance, but do not leave disabled permanently—motor damage or drive damage could result.