Mains failure
Danfoss · VLT HVAC Drive FC 102
What does 36 mean?
The frequency converter has detected a loss of incoming supply voltage, and the 'Mains Failure' parameter (14-10) is configured to generate an alarm. This indicates a power supply interruption to the drive, which will cause the motor to stop. Until mains power is restored, the drive cannot operate.
Common Causes
- Total loss of incoming three-phase (L1, L2, L3) or single-phase supply voltage to the drive.
- Blown fuse or tripped circuit breaker in the upstream power distribution system feeding the drive.
- Loose or corroded connection at the main power input terminals (e.g., L1, L2, L3) of the drive.
- Parameter 14-10 (Mains Failure) is set to 'Trip' instead of 'No function' or 'Freeze output' during intended voltage dips.
- Severe voltage imbalance or sag on one or more phases causing the drive's input monitoring to trigger.
Repair Steps & Checklist
Click steps to track your progress.
- 1
1. Check all upstream fuses and circuit breakers in the main power distribution panel.
- 2
2. Measure the incoming line-to-line and line-to-neutral voltages at the drive's L1, L2, L3 input terminals.
- 3
3. Verify the setting of parameter 14-10 (Mains Failure Function) to ensure it aligns with operational requirements.
- 4
4. Inspect all main power wiring connections at the drive for tightness, corrosion, or signs of overheating.