EL
ErrorLib
Brands
||
  1. Home
  2. Danfoss
  3. VLT HVAC Drive High Power
  4. 256
About·Privacy·Terms

ErrorLib — Industrial Fault Code Library

Disclaimer: ErrorLib is an independent technical reference tool. While we aim for accuracy, always verify with the manufacturer’s official service manuals before performing maintenance on industrial equipment. ErrorLib is not affiliated with the brands listed.

256

Internal fault (Power EEPROM data defective or too old)

Danfoss · VLT HVAC Drive High Power

What does 256 mean?

The power EEPROM data is defective or too old. This indicates a corruption or obsolescence of the non-volatile memory storing power section parameters.

Common Causes

  • Corruption of data stored in the power section's EEPROM (Electrically Erasable Programmable Read-Only Memory) due to noise or power fluctuation.
  • Degradation or wear-out of the EEPROM memory cells over time due to exceeding specified write/erase cycles.
  • Incompatibility between a new firmware version and the existing data format in the power EEPROM.
  • Internal communication error between the main CPU and the power EEPROM chip, leading to data access issues.
  • Manufacturing defect in the EEPROM chip itself or its associated circuitry on the power board.

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    1. Back up all parameters from the frequency converter (if accessible via control panel or software).

  2. 2

    2. Perform a factory reset (e.g., Parameter P14-22 Load defaults) to clear corrupted EEPROM data.

  3. 3

    3. Download the backed-up parameters to the frequency converter after the factory reset.

  4. 4

    4. Power cycle the frequency converter (main input power off for 5 minutes) and observe if the fault clears.

  5. 5

    5. Verify the frequency converter's firmware version is up-to-date and compatible with any recent changes or system updates.

Browse all codes in this manual (60)
Verified technical data. Last updated: April 2026

Related Faults

0Internal fault (Serial port cannot be initialized)17Control word timeout22Hoist mechanical brake
Source: Danfoss VLT HVAC Drive High Power
View Official PDFSearch more codes in this manual