Applicable Systems
Modicon M221 Modicon M241 Modicon M251 Modicon M340 Modicon M580 Altivar

Symptoms

Undervoltage fault: mains voltage too low.

Possible Causes

  • Mains voltage too low
  • Transient voltage dip
  • Input phase loss

Troubleshooting Steps

  1. Step 1: Measure mains voltage
    Voltage within rated range
  2. Step 2: Check for transient dips
    Voltage stable
  3. Step 3: Verify all input phases
    All phases present

How to Reset

Reset via control panel after voltage normalizes.

Source: Schneider Electric ATV320 Programming Manual

Category: PLC & VFD