Danfoss FC-302 Error Code 4

Danfoss PLC & VFD Major Phase Loss

Model: FC-302 | Code: 4

Applicable Systems
FC-30 FC-51 FC-101 FC-202 FC-302

Symptoms

Main power phase loss detected on input.

Possible Causes

  • Missing input phase
  • Input fuse blown
  • Loose input connection

Troubleshooting Steps

  1. Step 1: Measure all three input phase voltages
    All phases present and balanced
  2. Step 2: Check input fuses
    All fuses intact
  3. Step 3: Inspect input cable connections
    All connections tight

How to Reset

Reset via control panel or auto-reset after mains restored.

Source: Danfoss VLT FC-302 Operating Guide, Danfoss A/S

Category: PLC & VFD