Alarm 69 on a Danfoss VFD indicates a problem with the power card temperature. This means the temperature sensor on the power card has detected a value outside the safe operating range. It could be either too hot or too cold.

Here's a breakdown of the causes and troubleshooting steps for this alarm:

Causes:

• High Temperature:

• The ambient temperature surrounding the VFD might be exceeding its specified limits.
• Blocked air filters on the VFD can restrict airflow and cause overheating.
• Internal malfunction within the power card itself is less likely but a possibility.

• Low Temperature:

• In rare cases, the ambient temperature might be too cold for the VFD to operate correctly.

Troubleshooting Steps:

1. Check Ambient Temperature: Ensure the surrounding environment meets the recommended temperature range for your Danfoss VFD model. Refer to the user manual for specific values.
2. Inspect Airflow: Clean any clogged air filters on the VFD to improve airflow and cooling.
3. Power Cycle: Sometimes, a simple power cycle (turning the VFD off and on again) can help reset the alarm if it's a temporary glitch.
4. Monitor Temperature: If the alarm persists, monitor the temperature readings displayed on the VFD (if available) to see if it remains outside the safe zone.